1985 Z-28 with the 308's posi i want 373 what do i neeed?

 

UPDATE: thread was moved to trans board, ingore this post.
try the transmission board. to answer ur question, i dont know, but let me know wen u find out. i hav 2.73 and want to go to 3.73.

 

I'm pretty sure you'll need to get gears made for a 2-series carrier...that and, well, the install kit.

 

if you wanna go with gears lower than a 3.08 ratio, you have to get a 3-series carrier. You "might" be able to find 3.42's or 3.73's for 2-series carriers but don't count on it..thats very rare.

 

Richmond gears makes them for both right?

 

I think they do but are a little more $$ than the 3-series ones though...if you're looking for better performance traction wise, just get the 3-series carrier and you'll have a much wider gear selection and no more peg leg rear.

 

What car or rear end can I get a series 3 from that will accept my 28 splin axles btw?

 

usually the '89 up irocs, GTA, Formulas (some '88 too) or if you could scuff one from a 4th gen rear, that would probably be the best find as those cars came with much improved 3-series carriers.

 

Ok so any 4rth gen carrier is a series 3 and takes 28 splines? Also if it is a 2.77 (i think) posi from a IROC or something, that means it is a series 2 I take it?

 

Thanks for the imput i have no idea what you guy's are talking about (3-series carrier ) i went on summit tryed to find what i need carrier gear's install kit but i dont want to order the wrong parts so my car has a 2 - series carrier right? Can some one list all the parts i'll need carrier,gear's,install kit so when i get to the shop its all there thank you!

 

90camaro, if its one of the earlier irocs (85-86) with 2.77's most likely its a 2-series carrier.

 

19kilo, I see you have an '85 Z28 so changing your carrier to a 3-series one is a good idea in terms of you'll get WAY better traction as you'll have both rear wheels grabbing instead of one. As for the install kit, all you have to do is find a vendor (summit, jegs, ebay, randy's ring & pinion etc) and order a MASTER intallation kit for a 7.5" GM 10 bolt rear and that kit should have everything needed to install the gears and the carrier...the install kit usually doesn't come with gears and carrier though.

 

All 350 TPI cars had posi in them right? My friend has a 1989 iroc 350 tpi and I thought it was posi, meaning which gears does it have? Thanks guys im starting to understand.

 

seem to me like you're getting confused because you are mixing up or don't know the meaning/difference of the terms "carrier" and "posi"....they are the same things.

 

my car has 308 posi so that a 3 carrier right?

 

still doesn't mean its a 3-series carrier, a lot of the earlier thirdgens has 2-series.

 

ok so some 85 IROC-Z/Z-28 came with 277 slip some with 305 posi did any come with 3 carriers? How can i tell what i have?

 

the irocs from about '87-90 has 3-series, do a short burnout then get out and look at the drag mark, if you only see a mark from one wheel, you have a 2-series carrier.

 

I've done that to see if i had posi or not i saw 2 burn marks.

 

if you weren't the first owner of the car it was probably swapped out by the original owner or any other owner it may have had.

 

Dose it matter if u did it in revers?

 

you DON'T want to do that.

 

Let say i did and 2 black marks what is that?