i have an 89 Iroc with 2.77 posi, i was wondering how hard the switch to 3.42 or 3.73 would be. im wanting to get a faster launch and quartertime, but at the same time this is a daily driver. should i keep it the same or if not what gears would i still get halfway decent gas mileage? thanks

 

with the overdrive trans you can go 3.73 no problem, if its the 9 bolt you have then finding those gears will be pretty expensive, if its the 7.5 10 bolt then its pretty easy to get the gears, also have a pro setup the gears, its a percise job that need to be done. also im not positive but you may need to swap carriers but i dont know forsure, maybe someone else may know forsure

 

Finding 9 bolt gears and posi carriers is not difficult at all. I sell ratios up to 4.10 for 9 bolts. I also sell brand new series 3 posi carriers for 9 bolts. Now cheap is a different story. All the info is on my page at www.koolmeister.com

Going from a 2.77 to a 3.45 or 3.73 or 4.10 will require a series 3 carrier too.

Miles