That is a good sized difference, and sure to eat up some power. I went from a 10bolt 8.5" rear in my G-body to a Ford 9" and lost about 3 tenths. I did, however, also upgrade to a 3" drive shaft at the same time, which also absorbed some power. I'd expect you to pick up a bit with the gear and the posi, so I doubt you'll lose any overall E.T. Why did you upgrade the rear in a 14 second truck? The stock rear should be good for over 500hp in my opinion.

 

I wonder the same things. Counting pounds and "loss" has no point if the little lightweight stuff (IE 10-Bolt) can't hold up to the abuse.

 

I actually managed to gernade the factory pinion housing and gears. I figured that if I was going to upgrade, might as well go all out. It's just nice to have something that I won't have to worry about (hopefully). I just want to get this vibration straightened out.

 

If you simply used the 1500 yoke from the 8.6 on the 2500 9.5, you wouldnt have needed that bastard conversion ujoint.
the 8.5/8.6 yoke is a direct fit on a 9.5" pinion/seal assembly.

You need to get some heavier u-joints now so that your driveshaft ujoints are as strong as the rearend.

A 10 bolt with 500hp in a 4000+ truck, yeah right. I have a 14 second truck and I break 10 bolt components all the time. MAYBE if you add aftermarket gears, axles and carrier. Stock stuff will have ZERO durability at 500 hp in a 4000+lb truck.

I will be installing the 14bolt 9.5" SF rear as well. I will be using the heavier u-joints and 14 bolt yoke.

peace
Hog

 

Care to tell me how mine survived for a long time under 500f-lbs in a 5300# truck and how Parish's 10 bolt lasted with over 1000ft-lbs? What component are you breaking all the time I bet it isnt an axle, most kill teh G80 thats a given but very few break the gears much less the axles unless you are doing something stupid.

 

I actually managed to gernade the factory pinion housing and gears. I figured that if I was going to upgrade, might as well go all out. It's just nice to have something that I won't have to worry about (hopefully). I just want to get this vibration straightened out.

 

Dude... why'd you double post 45 minutes after the first one? Exact wording, quotes, all.

 

sho 'nuff... yea, ya right!


*edit* damn... now I saw 1slow01Z71 post here a second ago.
You got delete rights? It's all trickery, man!

 

Your pinion angle is off. More than likely you will need to nose the diff down a bit. Possibly install 2* shims with the fat side to the back.
The bigger diff may have a different angle that the axle pads are welded on that the leafs rest on.
One other thing you might want to check. Make sure that the pinion nose is the exact same length as the smaller diffs.
If it is longer, you may be placing your u-joints in a bind. Just a thought.

Jim

 

all good info to knwo when i install my rear