O/T, 1980 Chev rear end change DONE

old · Dec 14, 2009

I hope. I have not taken it out for a test drive yet but should be done. I hate bleeding the brakes by my self but got that done. Guess that is why I got that vacuum pump a couple decades ago, fun to find when you only use it once every 15 years or so.
Now for the odd ball question. After looking at things better I found the rear end I took out was a 13 pinion and 40 ring gear which makes it a 3:07 and the one I put in is a 14pinion and 43 ring which also makes that a 3:07. So which one is the stronger rear end??
Well guess I'll be ready to haul hay now

Uncle Ernie · Dec 14, 2009

I would think that the gears with the higher tooth count would be larger/ heavier/more durable. Good luck with your repair!

trucker40 · Dec 14, 2009

So did you change housing and all or just the hog head?I guess if you had to bleed the brakes the whole thing.Did the yoke bolt up or did you change the u joint?If the u joint worked then it probably is not any different than the old one.If you had to change it then the smallest u joint is probably the weaker one.

chevytaHOE5674 · Dec 14, 2009

Count the cover bolts. I'm guessing it was a 10 bolt and you now have a 12 bolt or vis verse. Neither one is known for its strength.

old · Dec 15, 2009

Both are 12 bolt so nope that is not it

old · Dec 15, 2009

I changed the whole thing so I would not have to set back lash etc. Same u joint on both and both are the 12 bolt rear ends only thing different in the 2 of them was pinion and ring gear tooth numbers

Oldmax · Dec 15, 2009

Old what do you use this truck for if it is anything other than to go from one place to another "like a car" that 3.07 isn't going to be that good. I had a GMC once with a 3.07 in it and if you loaded 1000 lbs in it you had to slip clutch to get it started. We had one in a FWD at work and had to use the granny gear in the 4 spd any time we were off road . I'm not knocking your truck but some times a higher gear don't help you to get better gas mileage as you are lugging the engine the most of the time. In the hills here in WV they used more gas than say a 3.5 or 3.76

old · Dec 15, 2009

This is a $x$ truck so I have to keep the gear ratio it came with. As for hauling I have been scaled out at 14,000 more then once and it does just fine. Ya when loaded I start out in granny but unloaded no problem starting out in first or as I call it 2nd. I can do around 60 mph in 3rd and never had it topped out in 4th. I do get when it it tuned up around 17mpg

O/T, 1980 Chev rear end change DONE

old

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Uncle Ernie

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trucker40

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chevytaHOE5674

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old

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Oldmax

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old

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