Rear end question
 

My friend has a 86 swb GMC 1/2ton with 2.73 gears, he also has a posi rear out of an 84 Trans Am. Are the rearends the same, can he swap just the gears? Inquiring minds want to know.

Re: Rear end question
 

If there both 10 bolts. I believe they would be the same housing so i see why not.

Re: Rear end question
 

84 Trans Am is a 10 bolt but the ring gear is a 7.5" or 7.625" where the 10 bolt corporate rear in the truck is a 8.5" ring gear, so the answer to your question is no, you can't swap gears. I'm pretty sure 81 was the last year the 8.5" ring gear was in the F bodies.

Re: Rear end question
 

what if they move the mounting points would that work. If they are the same length

Re: Rear end question
 

The 2 rear ends dont have much if anything in common besides the 10 bolts.

The best bet if you want to go all out with gears and posi is to find a used 12 bolt and have it rebuilt with the gears and posi unit you want. You could do this with the 10 bolt but I personally wouldn't feel good about investing money in a 10 bolt as it's not as strong. If you only plan to run a stock 350 for street driving though, a 10 bolt is fine. Since you want to put in a posi and lower gears, it sounds like you want to go fast, so a 12 bolt would be the best option.

Re: Rear end question
 

Not to mention the small 10 bolt from the car is very WEAK.

Re: Rear end question
 

I dont know why people dont like the chevy 10 bolt , like an unwanted red head step child.

My chevelle has a 10 bolt and when the car was running I drove the car like a race car (speed scares me but 100 in the car) mud truck Got stuck in a car show just hit the gas a through some mud) and a rally car (lot of gravel roads around here 85 most of the time and drifting corners).

Just my 2 cent all my 10 bolt have dont very well except for the one in my old 86 c10 the rod in the main case bored to hole from being round to oval. But that can happen in a 12 bolt to.

Re: Rear end question
 

So is their any rear end that you can slide into place and have posi i know 10 bolts are ok because i had a 82 long bed that was a 10 bolt posi and i beat the crap outta it but all asideis their any rear end that will fit my 80 chevy long wide 1/2 ton

Re: Rear end question
 

A '73-'87 half-ton rear should bolt in, except for the driveshaft. The 10-bolt has a longer "snout" than a 12-bolt, and most likely will require a shorter driveshaft. My 10-bolt ('84) also had a larger U-joint than the old 12-bolt ('79), so I had to get a conversion U-joint.

Re: Rear end question
 

something else to think about: i had a 71 cutlass with a 10 bolt rear and i bought it a posi from an 80s half ton truck. it had a 31 spline axle and the car 10 bolt had a 28 spline axle. i dont think that the car and truck posi are compatable because of that reason.