68 rear end gears

[68RAT]

Thinking about changing the rear end gears instead of the TKO tranny. (maybe later for the tranny) What gears will fit in the '68? I'm running 3.70's right now and thinking of going to at least 3.08's or even higher if possible. Also is there anything else I need besides the gears? Maybe rebuild the posi?

68RAT

 

[Beagle 1]

Thinking about changing the rear end gears instead of the TKO tranny. (maybe later for the tranny) What gears will fit in the '68? I'm running 3.70's right now and thinking of going to at least 3.08's or even higher if possible. Also is there anything else I need besides the gears? Maybe rebuild the posi?

68RAT

I think that 3.08 was the highest gear available stock. Probably something higher available aftermarket. 3.08 will run at about 2800 rpm at 70 mph with stock height tires without overdrive, if my tach is correct. Not bad IF you've got the low end power. Geared a little high with a Muncie 4 spd for off the line.
With my 69 427/390, I'm thinking of going from the origional 3.08 to 3.23 or 3.36?? when I need to rebuild, which will give me a little more low end, and still be useable on the freeway.

 

[Garys 68]

68s came with 3.08 in the auto cars. 3.36 was the min ratio in 4 speeds. 2.73s were available in autos of later years, but I'm not sure if those were in the old iron housings of the earlier vettes.
But the 3.08s will work fine, although I agree, they are a bit high for the Muncies 1st gear. And you might as well go through the posi while you're in there.