Grain truck muffler

Hi guys. I got the ford grain truck up and running. Thanks for the
help with the broken off fitting in the oil filter housing. The person
that suggested the pound a torx bit in was right. It worked
perfect. My question is how do I know what muffler to put on the
truck. It’s a 1966 ford f700. I just put a 391 engine in it. Do I just
go to fleet farm with the size of the pipe and purchase one the
same length? I appreciate your help

That idea will work well Measure the exhaust pipe where it ends (assumes it is pretty round and of good metal strength). measure carefully to assure the OD is measured because the ID is not used on an inlet to a muffler. Look to see how far it is to the next hanger bracket, or place to attach one. ANy length between the overlap at the front (exhaust) pipe, and that bracket will work. This likely ends the whole system, so purchasing a down turn end to fit the new muffler outlet is a good idea and looks finished. Purchase 3/8 rod size clamps for both ends, and a rear hanger if needed. Rusty hanger bolts might need replaced as well! Jim

Must be you have a good "y"/exhaust pipe?

(quoted from post at 10:12:00 12/26/20) what muffler to put on the
truck. It s a 1966 ford f700. I just put a 391 engine in it. Do I just
go to fleet farm with the size of the pipe and purchase one the
same length? I appreciate your help

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I just went with a pair of 'glass packs" on the International. They are no more expensive than mufflers and take up less space. Plus I like the sound. I've had good luck with them. Must be close to 30 years they have been on the truck and I only see one pin hole leak in one of them.

What grain? If wheat, I would put on original type muffler for better spark arresting.

(quoted from post at 11:29:53 12/26/20) What grain? If wheat, I would put on original type muffler for better spark arresting.

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We've driven the Loadstar through a lot of cereal grain harvests and never a sign of a spark from the glass packs. Some people claimed the Loadstars were "stubble burners" because the original mufflers hung down low enough to contact high stubble. That was one reason I went with the glass packs. Very slim and sit higher than the original mufflers did.

Good advice.

Trying to save money by re-using old rusty bolts and clamps can make a quick job turn ugly fast.
Take the old stuff off with an angle grinder or the torch.

I think the answer that you want is...."It depends..."
Anybody here, as a kid, drive a big V8 grain truck, coast down a hill, shut the key off for a few seconds and then turn the key back on? Did your mufflers survive?
If you want the economy route and you want to save some money on the install, glass packs might be the way to go. Horsepower wise, you PROBABLY won't have the highest with a glass pack. Yes, they sound smooth and mellow to young ears, but compared to other mufflers, these are usually more restrictive.
A big stock-type OEM muffler will be the quietest, but is probably the most expensive. Most of the older, bigger Fords have a tendency to backfire when you use the gears to de-accelerate. Is your distributor in good working order? If you have no backfire and want it quiet, the factory type muffler is the way to go, provided you want quiet and don't mind the price.
If your truck backfires, at all, you might also want to consider a thick, welded muffler available from the speed shops and mail order catalogs. They are almost indestructible.
Here's what you DON'T want to do: In the early 80s, I was a kid right out of tech school and was working at a mom-and-pop type of gas/service station. It was in a farming community and the area farmers were TIGHT. In comes a guy with a Chevy grain truck that had a big block in it, IIRC, probably a tall-deck 427. It had an exhaust in it with a single muffler and he brought in a Walker Scottish muffler or perhaps it was called Royal Scott. It looked exactly like a glass pack except this had no fiberglass in it. If you looked inside this muffler, you could see the exhaust took the path of a regular dual-180° muffler. In other words the exhaust went forward and back inside the muffler a few times, except the pipes inside this muffler were very small. I showed this feature to the farmer and he said he didn't care. In other words, "Put it on!" A day later, he came back with the muffler in his hands and told me that I had somehow failed to get the clamp tight on this muffler. I knew better. This muffler was so restrictive, it blew off because of back pressure. Again, he told me to put it back on and this time he told me to get it right. So I installed his muffler, clamped it down tight (like I did the first time) and I then drilled three small holes through the muffler input tube where it slipped over the exhaust pipe and I put three sheet metal screws through the muffler's input tube. These sheet metal screws made sure that this muffler never blew off again.
I'm sure there was a loss of horsepower, but the farmers saved a couple of bucks on his exhaust and he never came back again for exhaust work.

My grandfather ran a few GMC with 366 he had stainless steel mufflers build in welding shop. He would trade trucks around every tree years. The trucks ran daily all over southeast and a trip out to Oklahoma weekly at three years old the trucks would be wore out....he always kept the stainless mufflers put on new trucks...Mufflers got changed with truck beds.

I totally agree with rusty6....glass pack is the way to go. I used them for years with good
results.

When I was young and didn't have much money (now I'm old and don't have much money), When I needed a muffler for a farm truck, I measured the pipe and got a tractor muffler that size and put it on. They were cheaper!!

Yes they are, i had a custom combiner, he had a Load Star , the emergency brake boot was shoot, and i seen it happen, the front ax boomeranged it back to the y cross over, it sat on their, and thats how it started, a fire in my field! It was a nice 100 bushel per acre Oats field, good thing my brother had a tractor and disk close buy to stop it! The only thing i will admit it was swathed a little to high.

(quoted from post at 16:43:39 12/26/20) the front ax boomeranged it back to the y cross over, it sat on their, and thats how it started, a fire in my field!! The only thing i will admit it was swathed a little to high.

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Mine has no Y pipe. True dual exhausts with a separate pipe to each manifold. Closest we came to fire was when crossing over windrows of combined flax straw the drive shaft picked up a little which of course turns into a huge bale in seconds. It rolled up so big around the drive shaft that it caught and broke off one of the hydraulic hoses to the hoist cylinder. Lucky we were'nt on the road as that straw wrap might have got hot before anybody noticed.

(quoted from post at 16:38:23 12/26/20) When I was young and didn't have much money (now I'm old and don't have much money), When I needed a muffler for a farm truck, I measured the pipe and got a tractor muffler that size and put it on. They were cheaper!!

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Bingo!!! I've seen several trucks with mufflers that appeared to be for a Farmall M.

What they call Turbo mufflers.

Quieter than glasspacks, and (supposedly) less restrictive.

They are larger, so take that into consideration.

Fred