67rally

iTrader: (5)

I just did an LQ9/T56 swap in my '67 Camaro this year and love it, but I'm still running the old gear ratio in my rear. I had it dyno'd at 458/410 to the rear wheels.

The rear is a GM 12 bolt posi with 3.31's. The T56 is out of a GTO, so it has a 2.97 first gear. Everything I knew told me 10:1 was the ideal ratio and this combo gives me a 9.83:1. Also, I find the .57:1 6th gear pretty useless until you get close to triple digit speeds.

This is a not my DD, just a fun weekend/nice day car. 99% street driven. I was thinking about 3.73's or 4.10/4.11's. Looking for a nice bump in acceleration. Any real life advice is welcome. Thanks.

1981TA

iTrader: (7)

With the 3.73s in mine, I was cruising at 80 MPH @ 2000 RPM in 6th, with a .50 overdrive. I guessing, if you don't mind rowing the gears a bit, 4.11s will give you the kick you want, while still giving you decent highway cruise RPMs. 3.90 might be a good choice too.

67rally

iTrader: (5)

I think the 3.73's would be an easy swap.

I didn't even think about 3.90's. Are those 3 series carrier compatible? I know the 4.11's are a 4 series, and would need a carrier change.

01ssreda4

iTrader: (96)

I'd go with the highest gear available for your series carrier for simplicity reasons. What size rear tire are you running?

67rally

iTrader: (5)

275/40/18's on the rear.

01ssreda4

iTrader: (96)

Most like 4.10s, but some complain it makes the lower gears useless......I always liked it though.