I can tell you my '70 Cuda has 4.56's with a 28" tire and it turns 3600 @60mph. I borrowed a set of 3.55's once and those brought it down to 3000@70mph.
On a side note, I installed a Gear Vendor and with the 4.56's its 3000@70mph.
Wow, wonder what the hell I can expect to see with my 4:56 gears and 26 inch tires? LOL
Only had this car out for short spins in the Fall before the snow flew. I will be looking for another center section with more streetable gears for sure.
