Ive got 3.31s in the chevelle now. and like the take off etc. The camaro has 3.08 ratio. with a small block 400 and turbo 400, it gets up and goes fine for tooling around on the weekends. Ive got a 12 bolt that I was told was a 3.07 ratio. Well I go to sell it and decided to check the ratio by pulling the cover, it turns out to be a 3.31. Now will I notice the difference with the same motor? Or is it worth the expense of the swap besides the bragging rights. If I install it, Im ordering a lockright, its drilled for 1/2 inch studs, so I need those too. Eventually im going to install a 60 over 396 in it. thanks! I figure its going to run about 400 bucks for the lockright, studs and fresh brake parts. Im just trying to justify it to myself. jim

It won't be very noticable. 3.08 to 3.55 you'll feel the quicker to a set MPH The 3.31 will be different, but not very noticable. They are both pretty much performance/economy gearsets. The difference will be less than 200 RPMs at 60MPH

So, the practical side of me says to sell it (got a guy willing to pay $800 for it). But the gearhead side of me says to order the lockright, studs and just install it. Most 2nd gen camaros arent running 12 bolts, and dont need to, but when you peak under the car, it just subtlely says performance.
I guess im ordering the lockright tonight. Jim

keep it Jim, it's worth more than 800 anyways.

plus the 3.31's are very desireable now

I went from 3:31 to 3:73 and did not notice anything other than the rpm's out on the highway. Considering going back to the 3:31's, but am going to give the 3:73, at least a couple more trips to the track before deciding.

I went from 3.08's to 3.55's and I noticed a big difference. I think it's a good middle of the road gear set. I used it on my 396 and it seemed to have a few more RPM's on the freeway.

3:31's,the best all around gear ever made for bbc muscle cars if your not running an OD trans of some sort.

I have a mild 396 with approx 370hp/430lbs trq with m20 and i went from 307 to 331 gear in my 12 bolt posi approx 2 yrs ago.

Yes i did notice the difference ,it wasnt huge if your looking for all out perf on the 1/4 mile strip but non the less the car felt like it had more spunk in the old BUTTOMETER & the motor felt like it gained some HP when it really didnt,thats the noticeable diference i felt.

Also for me going from 307 to 331 gear stopped the real anoying shifting from 3rd to 4th back to 3rd then back to 4th when i was stuck in traffic that goes from like 35-45 mph which happens a lot where i live,it cut the shifitng back & forth by over 50%.

With 26" tires M20 & 331s the motor turns approx 2650-2700 rpms @ 60mph,but with the 307's it was approx 2400-2450 rpms & 60 mph.

But i would not run any more gear then 331 on the street if your going to do a lot of crusing unless you have an OD of some sort .

Scott

i didn't read the whole thread so please bear w/ me!!

3.31's and 26.5" tall tires are probably dead-nuts on to a stock tire height of 25.3" to 25.5" and 3.07's if you wanna check!

At least my 1st Gen. Camaro car is.

pdq67

Not sure of the tire hieght, but Im running 275 60 15s on both the SS wheels and centerlines, that I switch back and forth. Jim

Put it in there.

Not sure of the tire hieght, but Im running 275 60 15s on both the SS wheels and centerlines, that I switch back and forth. Jim
28" tall

Call me an old fart (35), but for a non-od trans I would have to agree that 3.31 are about as short as I would go. Even with 28" tires and an M20 (1:1) my car still rev'd more than I cared for. I coulda used another gear AROUND TOWN! I dont know how you 3.73+ guys do it...on anything longer than a driveway.

What Vince said all the way,unless your running an O/D unit or going racing every Sunday any more gear then 3:31 on the street is just not friendly at all. Too many rpm at cruise watses fuel,increases motor heat & cabin noise,mor wear on motor and associated accesories like alt,w/pump/mech f/pump/p/s pump,etc.

Iv'e had the 3:31's in my car for the past 2 seasons but may consider going back to the original opt 3:07 gear my 12 bolt came with. This is becasue now i find myself having to drive on the interstarte @ 70mph (sill getting run over at that speed on a 55mph limit in NY)

I had 3:73 on steet when i was a kid in HS,even then it was a pia with fuel consump (@ 21.9 cents per gal IN 1971-72 not like now with 93 oct @ $3.50 per gal)& motor noise in car,now i could put up with 3:73s for about 30 mins.

Scott

What Vince said all the way,unless your running an O/D unit or going racing every Sunday any more gear then 3:31 on the street is just not friendly at all. Too many rpm at cruise watses fuel,increases motor heat & cabin noise,mor wear on motor and associated accesories like alt,w/pump/mech f/pump/p/s pump,etc.

I had 3:73 on steet when i was a kid in HS,even then it was a pia with fuel consump (@ 21.9 cents per gal not like now with @ $3.50 per gal)& motor noise in car,now i could put up with 3:73s for about 30 mins and thats it.

Vince,you think your an old fart at 35,then what heck am i at 51 still wrenching & pulling gears (only once in a while & not too hard/cant afford to break a #'s matching drivetrain/car) in these old muscle cars.

Scott