I have an 87 camaro with a stock 350 carbed & 700R4. I have a 9 bolt rear on the car, I need to replace the gear set and was thinking of going from the 3:23 that is in there now to either a 3:42 or 3:70. I have plan's to add H.P. down the road (2 yrs) and rebuild trans. I know I will lose mpg and speedometer will be off, is there any other problems I may have untill I upgrade motor and trans. I am shooting for 350 - 400 HP once I am finished. Where can I get a new 9 bolt gear set. THANKS

 

9 bolt stuff is hard to find. I believe 9bolt.com was back up in operation in australia. Shipping is likely high but i believe some members used it recently with success. If you do have 3.27 gears factory then you Need to find a gear set in 3.45 or 3.70. If not a 3.27 rear and it is a 2.77 need a carrier and gearset. I think some aftermarket company made 3.70's but no one made 3.45's. From time to time you will find 3.70's used or new old stock in the forum classifieds. 3.45's rarely show up.

Depending on rpm range and hp, hard to beat 3.70's for street strip fun

 

Thanks, I am sure I have 3:27s, What would 3:70s do to my rpm say at 70 mph in 4th with 700r4? Right now it's about 2400 rpm at 70. Is there a way to somewhat calculate how much higher they would be?

 

It will be about 200 rpm higher.

 

I've got a 3.27 geared 9 bolt now, and it's a good rear axle. That being said, I was considering either a Ford 8.8 conversion, or a fully beefed up 10 bolt. The 9bolt stuff is just too hard to find, and when you do, it's used and expensive. If it was bulletproof, it might be worth it, but once you convert to something else, parts are relatively cheap, and available anywhere. Food for thought.

....and be careful you don't go too deep on those gears, assuming you're gonna keep it with a long tube TPI. With such a small powerband, using your rear gear to keep it going longer can really help. My goal is a 3.42 gear, which sounds like what you were thinking too.

 

The only thing I am sure of with what I will do motor wise is sticking with a carb.I really don't want to get into all the computerized stuff, I want to keep it simple.
Thanks

 

Ah yes, you DID say carbed. You'd be fine with 3.73/3.70's

 

Randy's Ring and Pinion also carries 3.70 gear sets (Yukon Gears) with bearings kit.

TA Performance sells a 9 bolt rear girdle and ARP main cap studs are an added option.

Before doing anything I'd recommend doing a posi check to make sure the friction cones and everything are in working order.

I spent $600+ in parts just to pull mine apart to find broken spider gears and decided to just swap in a free 10 bolt.

Are you planning on doing the gears yourself? Normal labor costs are $300-$800 around here.

 

Let me warn you, as far as I know ALL of the 9 bolt 3.70 gears make noise. Don't do this thinking that it's going to be a quiet gear. If you can put up with some gear noise then go ahead. If not then don't use the 3.70.