Bought a 56 Chevy truck with I believe to be a Camaro rear end. These are the numbers on gear . I guess a 2.78 gear ratio. Hard to make out the 3..
2.78 gears.....ready to go land speed racing? If the engine it will continue pulling to 5000 RPM, with a 29 inch tall tire and a 1:1 top gear your truck will do 155 MPH Lynn
I will let you know lynn. I bought a 3.08 rear to put in it. I will rebuild it then swap them. I will be running 28 or 29 tire. No overdrive.
2.78-1 to a 3.08-1 ratio change isn't worth the effort. Minimal change with a lot of work. No bang for your buck. Not knowing just what Camaro model and era that rear end is from, I would at least do 3.42-3.55 range with a 28"-29" tire. 3.73 range will limit your highway speed with max RPM. Bill
I don't mind 3.08 or 2.78. I can drive it while I rebuild other rear. Thought I had 3.73 wanted to go higher. It will pull a 3.08 fine.
My 250 likes the 3.08 gear ratio with 28" tires, it will run all day long at 2400 rpm and 65 mph with no overdrive. The engine doesn't have enough power to pull an overdrive and 3.42 gears just used more fuel and raised to rpm above a comfortable level.
Leave it alone and install a more modern wide ratio trans [Borg warner Super T10] A "Z" ratio ST10 with 3.42 first and 2.78 rear is exactly the same as a Muncie M20 first and 3.74 rear. But you get the highway cruising advantage of the 2.78 rear
I bought an early Camaro rear and was told it was 3.08. Got it home, opened it up and ... UGH, 2.56. Installed in anyway, behind a TH350 and it worked fine. I believe I had a 305 SBC in that one. Never had a tach in it so don't know what the revs were. Drove fine and even pulled a small trailer at times.
2.78 gear with a 29" tire is 2,255 rpm at 70mph. 28" tire is 2,335 rpm. I have a shoebox with an 390 FE with a C6 and will be running a 2.79 with a 28.5" tire.
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