GM pickup diesel engine switch

How terrible of a job would it be to put a gas 350 in a 92 chevy pickup with a blown 6.5 diesel? I have a complete donor pickup (wrecked). thanks Lee

I would guarantee you that it would be a bunch of work...and what you would end up with might be tough to get licensed if you have to go through vehicle inspection to get your license tabs.

Some years ago, a friend of mine bought an almost new, recovered stolen Ford pickup that was mostly there except for the diesel engine, transmission and the tires and wheels, which had been removed by unknown persons before he got it. He didn't have a diesel engine, so he put in a rebuilt 460 gas engine and automatic transmission out of a Lincoln that was 5 or 6 years older than the pickup. He did a real nice job, and the truck looked factory and ran great. But he lived in the City of Spokane, and had to go through emissions inspection in order to relicense the pickup. Since the pickup VIN was for a diesel, the no-humor-at-all inspectors said it could never pass running a gas engine. He did a bunch of appealing to the authorities, but finally was told that the conversion to a gas engine would require him to have ALL of the gas gizmos and an engine the same year as the chassis for it to pass. Since his earlier engine did not have a bunch of that stuff and it would have cost a whole lot of money to do what they wanted, it never did pass. He finally gave up and sold the pickup, for about half what it was really worth, to a guy who lived in Idaho, where they did not have to mess with the inspections. He wished he had just replaced the diesel engine with another diesel, or never had got involved with the project. He had many, many hours in it, and got nothing at all for his time.

Live and learn...good luck!

Might want to ask your local GM dealer about a Target motor. They used to be pretty reasonable.
One of the drivers here has been buying Hummer diesel take outs from somewhere that are low mileage and putting them in his boats.
If you can't find a replacement motor for yours, I can ask him where he is getting them from.

Would a 350" Oldsmobile fit easier? Thats what the diesels evolved from. Much better engine, service lifewise, than the chevy.

Piece of cake ! No inspection here in Iowa . Plus , it would more than likely be lower emissions than original 6.5 . the olds motor is a dog and pos to work on compared to Gm 350.

The 6.2 and 6.5 Chev diesels did NOT evolve from the POS Olds 5.7 diesel. NEW design entirely. Look at a 5.7 and a 6.2/6.5 side by side, NO comparison. The 6.2/6.5 are more closely related to the Chev big block gas engines (396,427,454) than the POS Olds 5.7. The 6.5 has the Chev bell housing bolt pattern.

Change everything including electronics from the donor truck

4.3 and 5.7 diesels evolved from Olds gas engines. The 6.2/6.5 diesel series was a new, ground-up design created by Detroit Diesel and has absolutely nothing to do with Oldsmobile.

Ought to be an easy swap. You can leave the diesel vacuum pump out and install a vacuum reservoir instead - hooked directly to the engine. Brakes are hydroboost already hooked to the power steering pump. Gas engine-to-trans is the same bolt pattern as the diesel. The trans may need some tweaking - but most of the swap will be "bolt in."

I wouldn't call the Olds 5.7 diesel a POS. After GM wised up, beefed up the bottom end and put roller cams in them they weren't a bad little diesel--in a passenger car. I owned several, two Olds 88's and one 98, and had good luck with them all. I drove one of the 88's to California once and went 4,000 miles on $118 worth of diesel fuel. (Good old days).

I wouldn't have put one in a pickup, but I heard the 5.7 into a full size Dodge van made a nice swap.

We had a nephew who had a full size Bronco with a 400 gas burner in it. He and my wife squared away at a stop light once with my wife driving one of the 88 diesels. She smoked him thoroughly.

The poor kid had two indignities heaped onto him. He got beat in a drag race by his own aunt, and she did it with a diesel.

stay with the diesel. you still have the 6.2 with the mechanical injection pump. it is the most relyable of them all.I would rebuilt it or buy a longblock if you cant DIY.
{Kennedy diesel} would be an exellent choice for a quality block.

I bought a 1979 Scottsdale Chevy 1/2 ton in 1982 that had low milage and had been bought by a farmer new with the diesel engine. He said the truck spent more time in the shop than time on the road. He had a local shop to install a 350 gas Olds engine in it. Then the farmer decided he didn't want the truck after the conversion.

I saw it advertised in the paper and went down to look at it and bought it. The shop that did the conversion said it was an easy swap. The truck
performed very well and never saw another shop.

I only had it a few months and was struck broadside when a man driving a Caprice Chevy lost control on the ice. His insurance paid for the repair. The shop took out one of the battery's
when they made the swap. I sold the truck in 1997
to a Warrant Officer that was being transferred to Ft Carson in CO. That engine was out of a 1975 Olds. Hal

I know a guy who rigged up an Isusu(sp) to replace his 6.5. It wasn't a neat job but it worked and he drove that truck for quite awile.

I know it has BOPC bell housing, I believe it has sbc motor mouts, however. It may have undergone some much needed improvement from the 350 olds block, but it was more of an evolution than a clean sheet creation. If given a clean sheet, I doubt anyone one with a non-crackerjack sourced engineering degree would have taken the V8 thinwall parent-bore approach, even a g.m. engineer. And a "detroit diesel" sticker doesn't make it a detroit, no more than a John Deere part # made a Hercules designed vertical twin a "johnny popper". Gm also did this to the neutered and deliberately service life limited 8.2L engine, basically a scaled up 6.2L.

Even the 6.5's were notorious for splitting from the mainline to the deck. The one I saw had a crevice that started beside a main journal bulkhead, about a quarter of an inch wide, and terminated in the cam galley at the top of the block. Filled the oil pan with coolant the instant it let go. Stock engine (w/turbo) in a 90's van with less than 20K miles.

They would last a couple of hundred K miles w/out a whistle, @ 155 horse. Not exactly "world class", as advertised by G.M. Not to mention that they were often coupled to the th700r4. I'll agree with you that in a pass. car application, they were workable.

I had a 1983 ? chevy truck with a 6.2 diesel. Bought it new and what a POS never want to by a GM again !
I swapped in a small block and it was pretty easy. Used the motor mounts right off the 6.2 and all lined up nice. Had to make a upper radiator hose and an adapter for the lower one. Had to modify my power steering bracket for the larger pump to fit in. Just installed a jumper wire in the converter lock up connector so it controlled itself.

Best thing I ever did was sell it off around 1996 ? and bought a used 1996 Dodge Ram 2500 with 360 gas engine. That Dodge was and still is a far more trouble free truck then any GM I ever owned. I'd say sell the GM off as a parts truck and go buy a Dodge ! prices are really cheap now for used trucks.

350 gas replacement? Use a pre-1982 HEI distributer to avoid computer ignition controls. Basic 4 barrel carburator and if block has engine fuel pump access and cam use it- otherwise a 10-15 pound electric fuel pump. Basic hot rodding, check your local laws on emissions checks. RN.

After the problems and costs of four Olds diesel engine series - and the sucess of the Mercedes 300D diesel - GM asked Detroit Diesel to design, from the ground up, a lightweight V8 diesel that would be a bolt-in replacment for the 305 gas engine. That is where the original 6.2 diesel came from. All the rest is pure BS.

Also - about your comments about thinwall design. The 6.2 was not thin wall. That didn't happen until the second year of the updated 6.5.
6.2 cylinder walls aren't any thinner than what was used in the 2.2 liter Isuzu diesels GM used in Chevy LUVs, Chevettes, etc. I still have a few - still running fine.

About the John Deere L to LA engine - when they basically copied the Hercules two cylinder engine - I agree.

As to the source of the 6.2 series versus the older 5.7? Seems you don't know what you're talking about.

Original 5.7 diesel got its start as a private homemade project done by a couple of Oldsmobile engineers - on their own time. When the fuel crunch came - GM and Olds took over the little project and put it into mass production. After Mercedes came out with a reliable diesel -late 70s - GM gave Olds 18 months max - to come up with a lightweight diesel as a "bolt-in" replacment to existing V8s. Around the same time - Ford asked International Harvester about a V8 diesel for use in small and medium sized trucks.

With GM, after the many problems, class-action law suits, etc. with the 4.3 and 5.7 Olds diesel engines - they did two things. First - they came up with the new, beefed up DX 350 diesel block to settle replacment engine claims. And also - GM hired Detroit Diesel to design a better, ground-up V8 diesel that would be lightweight and work as a direct fit and power replacement for the 305 gas engine. It was designed - and - at first - built in-house at Detroit Diesel. GM also - with Oldsmobile - came up with a V-5, 2.5 liter diesel in 1981 - but it never got used.

Original 6.2 has the same torque and horsepower as a gas 305 - just what GM asked for. And, only weighs slightly more by 75 pounds. And, if used carefully - worked just fine. I put 500K miles on one - but 200K is more of the norm. There were several, however, that had the blocks crack the the main bearing webs at 150K miles. This was later adressed by making the outside main-bearing cap bolts smaller - from 12mm to 10 mm.
Now - when the bore was increased to make it a 6.5, and the block was cast thinner, and a turbo added - not so reliable at a higher power lever. Especially with a cast-iron crank and thin cylinder heads.

Now - if you want to talk about the IH 6.9 diesel - that became the 7.3 used by Ford - it WAS an evolved gas engine. Made from the IH heavy duty gas truck engines - MV 404 and 446 gas engine series and retains the trans-mounting bolt pattern. IH started the project in 1978 with Ford in mind.

The 6.9L engine underwent a lot of development and durability testing before the start of production. A total of 160 prototype and 10 pre-production engines were built for engineering tests. The test engines accumulated a total of 52,000 laboratory durability test hours and 815,300 miles of field tests by the time Ford vehicle production began.

The laboratory tests included:* 21,000 hours at full load
* 16,500 hours at 72 percent load
* 4,500 hours of special durability tests
* 10,000 hours on pre-production engines

The 10 pre-production engines were built and tested on the dynamometer to verify the quality of the production process. Each engine was subjected to 1,000 hours (approximately 80,000 miles) at full load, with no problems occurring. In addition, pre-production engines were placed in customer fleet trucks and subjected to varied conditions, drivers, and use.

The "converted" gas to diesel 6.9 was built with heavy use in mind - the GM Detroit Diesel 6.2 was not. The IH/Ford 6.9 has a forged steel crank, heavy block, gear-drive cam, hardened valve seat inserts, etc. The GM DD 6.2 used a cast iron crank, lightweight block, timing-chain cam drive, and cast-in-head soft (but hardened) valve seats.

Original 6.2 diesel - 130 horse at 3600 RPM, 240 lbs. torque at 2000 RPM. Engine weighs 650 lbs.
Bore 3.98" and stroke 3.8"

Chevy 305 gas engine - 150 horse at 3800 RPM and 240 lbs. torque at 2400 RPM. Engine weighs 575 lbs. 3.7" bore by 3.48" stroke.

Original IH-Ford 6.9 diesel - 155 horse at 3300 RPM and 298 lbs. torque at 1400 RPM. Engine weighs 900 lbs. Bore 4" and stroke 4.18"

The IH engine was an industrial engine to start. It was less of a pos than the gm engine, but still a pos. The dt360 would have been a much better choice for ferd, if the HAD to use an IH unit. They simply took the same road as G.M., And that was to go with the lowest unit price, from the lowest bidder.

The cylinder walls of the gm engine compared to the equaly non-sleeved Cummins, are THIN. They are prone to cracking in high performance applications.(eyerolling giggle, what will a B series Cummins block withstand?)

What plant were the fourstroke V8"s of gms built in? A gm plant, or in Detroit Diesels facility?

Not really trying to start a conflict, and I agree that n/a versions will fare well under moderate use. I do not believe that Detroits engineering team was given a fresh start with the program. I believe gm imposed guidelines that allowed tooling and proccess from earlier platforms to be reused. The result was a lump of iron that made the green 92 series detroit engines look bulletproof in comparison.

Thanks for all the replies. What I was wondering was how hard it would be to use the 350 gas with the TBI and change some or all of the wiring harness and the ECM from the wrecked gas pickup. Lee

I won't dwell on how G.D. hard they were to start. Seems gm new about as much about combustion chamber design as IH did when they built the diesel/gas abortions.

I'd kind of hate to compare anything on a GM 6.2 to any Cummins. Cummimns is an industrial "B" rated engine. So is the Ford 6.9 and 7.3. GM 6.2 or 6.5 never was and never will be. That being said - Cummins made special repower kits for bread vans that came originally with GM 6.2s. Bolt-in replacement Cummins for the 6.2 is the 3.9 with a special adapter bellhousing that tilts the engine a bit to make it fit. Besides being very heavy built, the Cummins has a very long stroke that gives it gobs of low-end torque.

I was a diesel mechanic when the Olds diesels came out - and also when the 6.2s came out. 6.2s had plenty of problems - but thin cylinder walls wasn't one of them. That - was just about never an issue except with some 1994-1998 6.5s that have a rear head-bolt problem that caused one cylinder-wall to crack. A few turbo 6.5s also got some cracking due to drilling to install piston-cooling oil jets.
With the 6.2s - weak blocks that cracked main bearing webs, overheating while towing, cracking between intake and exhaust valves, crankshafts snapping in two or three, etc. WERE problems. But when used carefuly, many made it well beyond 400,000 miles and a few over 500,000. My 87 6.2 Suburban made it to 520,000 miles before it blew to pieces.

The original prototype and first short run (colored red) 6.2s were built in the DD plant. Then the later ones in GM plants. After that - the newer 6.5 engines and blocks have been made in many places including GEP (division of AM General), International Engines (formerly part of IH or Navistsar), Delco-Remy, etc.

The newest replacement engines sold for the military HUMVEEs, marine use, and/or older pickup trucks that had 6.2s or 6.5s - are made in Franklin, Ohio. The newest "6500 Optimizer" has a block with more metal and a higher nickel content along with heavier cylinder heads.

The first red-colored 6.2s, first used in model year 1982 also had a higher nickel content than the newer ones. How much more, I don't know. I've got half a dozen of the older blocks sitting in my shop and - with a grinder - they make different color sparks than the newer blocks.

The original prototype Olds 5.7s also had high nickel blocks - but due to cost-cutting - they never made it to production. Except -maybe - with the law-suit era DX replacement blocks that came out in 1981. I heard they were much better - but after the 6.2 came out, I didn't pay much attention to the Olds diesels. I do know they are popular to convert back go gas engines for racing due to their beefed up cranks and mains.

Back to industrial engines like Cummins - they are "B" rated. This rating predicts how long engines last when used hard as real trucks. 5.9 Cummins got a B50 rating of 350,000 miles. That means 50% made it that far with no major teardowns. Ford-IH 7.3 diesel has the same B rating as the 5.9 Cummins. The newest Ford-IH Maxforce diesel has a B50 rating of 375,000 miles. The Chevy-Isuzu Duramax only has a B10 rating - of 220,000 miles. That means 10% fail and 90% make it.

5.2 liter Isuzu beats them all. Has a B10 rating of 410,000 miles. The International Navistar DT-444E has close to the same rating -and it's basically a tweaked 7.3 with cast-in-block cylinders - no sleeves.

I've still got over a dozen 6.2 diesels including two snow-plow trucks, one Ford-IH 6.9, one Ford-IH turbo 7.3, a few Isuzu 1.8s and 2.2s, and a 92 Dodge W250 with a Cummins 5.9. The Cummins beats them all in every category. But, the Ford-IH diesels have been very rugged. Just tend to be fuel-hogs.

"The newest replacement engines sold for the military HUMVEEs, marine use, and/or older pickup trucks that had 6.2s or 6.5s - are made in Franklin, Ohio. The newest "6500 Optimizer" has a block with more metal and a higher nickel content along with heavier cylinder heads."

I've seen these. alot better. Is the pump still in the valley, under the manifold? Alot of pumps cooked over the years!

The parent bore in the cummins is way thick. No problems w/ cavitation. 7.3 was bad in that regard. The Cummins will support an amazing level of power for a shocking length of time. Guys are spending fortune on powerjokes & duramax's & not being able to make competative power. The duramax's cooling system is way inadequate, also. For my money, I'd still rather have a 6V53!

Pump is still in the valley and still a Stanadyne rotary. The US Military has had a miserable time with them over in Iraq with the high heat, and thin fuel. After they started adding armor to the HUMVEEs, they run even hotter with worse problems.

With the Ford-IH engines - cavitation was not a problem with the thicker walled and lower powered 6.9s. It all started when the 6.9s got bored out to 7.3. The 7.3s though seem to hold up fine if a coolant-conditioner is used.

With the 6V53s - most got condemned for being underpowered in my area with lot so hills. I still have two machines with 3-53s, and one with a 2-53. They've been rock solid engines - just little to no oil pressure at idle when hot.

Is there any way to extend the injection pump life and reduce heat?
Perhapes a heat exchanger for the fuel entering the pump?
How much fuel entering the injection pump at 100% power just bypasses and returns to the tank?

6V53TTA's power some very competetive drag racing pickups. 180hp in our ex-fire dep't 3600gal tanker, with an allison that slipped like snot on ice didn't work out well though!

Dt 360, or a 6-354 perkins would have been a much better choice for ford. Or a deal with mack or john deere.....can you imagine the marketing potential?

Add some oil to the fuel and hope for the best?
There is no getting around the fact that a rotary pump in a V-8 engine has to do MUCH more work than an inline pump.

At 2000 RPM - the one set of pump plungers in the rotary pump have to fire off 8000 times in one minute for an eight cylinder engine.

Take the same V8 and put an inline pump onto it - at 2000 RPM and each pump only has to fire 1000 times. That's a huge difference.

Besides that - an inline pump has no distributor section to wear out - and that's the #1 issue on the Stanadyne pumps.

Here's a part of an article from National Defense Magazine from July, 2004.

"Army Ponders New Diesel
Engine for Humvee Trucks," notes that maintenance nightmares have been experienced in Iraq
because engines regularly break down and often must be replaced after only 1,000 to 2,000
miles of operation. Much of the blame for this is placed on the bolted-on armor protection that
adds weight to the vehicles. However, the inability of the rotary-distribution, fuel-injection
pumps to operate satisfactorily for sustained periods of heavy-duty operation is probably a
contributing factor, especially when low-viscosity fuel is used in a hot environment. Interestingly,
the fuel-injection pumps in many, if not all, of the HMMWVs operating in Southwest Asia have
been retrofitted with Stanadyne's Arctic Fuel Conversion Retrofit Kit. This kit apparently has
done little to offset the significant increases in maintenance that have been experienced recently.
Rethinking the SFC
Combat operations that occur in higher temperature environments certainly will intensify the
operational and maintenance problems of diesel-powered vehicles and equipment with
fuel-lubricated fuel-injection pumps. Since almost half of the Army's diesel vehicles and
equipment have rotary-distribution, fuel-injection pumps, a solution is urgently needed.

Tbi wasn't really something desirable......An Edelbrock performer manifold, a 500-600cfm 4bbl, and hei would be better in every concievable way.

I have a nice 82 Chevy pickumup I got in S.C. that had a 6.2 with 4spd and loved it.Buddy of mine wanted it bigtime so I sold him just the eng.Took it out and put in a 350 gas allin one weekend.Had no problems at all.Easy job with no puter. Hoss