hey what gears should a 87 posi disc rear end from a firebird have?

 

350 TPI car - 3.27
305 TPI car 5 speed - 3.45

 

and thats a 100% sure its 3.45 cus if it is i will have a 87 disc posi rear end from the 87 bird that was 305 tpi manual in my stock 2.73 posi and boy i will see a diffrence

 

Those are the only 2 gear ratios available in the 9 bolt disc rear end in 87. It will be a huge improvement over the 2.73 rear, you will definitely be pleased with the change.

 

i thin kit a 10 bolt not 9

 

If it's a 10 bolt then it shouldnt be a 87..in 87 the only rears that had discs were 9's. Better go count the bolts.

 

I took it off a 87 bird but i guess ill count the bolts

 

Third gens came out with 9 bolt?

I thought GM only manufactured 10 and 12 bolt rearends?

Mine is out of an 86-87 z28 10bolt 3.73 & posi disc rearend.

 

In 87 all TPI cars were equipped with the 9-bolt BW 7.75" axle. Some Pontiacs got the 9-bolt before 1987 though.

 

yeah its a 9 bolt.are they any good besides they have the gears i want?how much power can they hold with good strong parts?

 

the 9 bolt is stronger than the 10bolts. problem is there is hardley any aftermarket for them.

http://9bolt.com

 

yeah i never seen much for it,but how much hp can it hold to the wheels 250?

 

Miles (the guy at diff solutions) is running a 500+hp 427 big block, on at least drag radials on his, and its still holding. but then again you hear of guys with TPI and bolt ons breaking them. like everything else it comes down to no abusing it, and how it is maintaned