: diff difficulties 86 brougham

04-18-09, 05:12 PM
As I am not conversant with the mechanics of diffs, am I able to gut the diff on the corporate 7.5" and replace it with an 8.5" or do I have to go the whole hog n replace the entire rear end
I understand that a cop car caprice would be the shot but would prefer it to just remove the internals of the diff with a posi 8.5"
As the power is coming from a 425 toro I am definitely after an upgrade of sorts

04-18-09, 06:46 PM
No, you have to change the complete housing. Nothing from the 7.5 swaps with the 8.5.

04-22-09, 03:46 AM
I wouldn't change it until it breaks, unless you gotta have a posi. They stuck that 7.5" rear end in LS1 fbodies, which had ~300whp stock. In the fbody, the 7.5" held up fine behind automatic cars with stock power. Things start to get iffy if you launch on sticky tires or had more than 400whp in the fbody though. Even then, there are guys with the stock rear making crazy power and running 1.4 60' times on the 7.5" Its kind of luck of the draw as to if it'll break when you mod your car.