I wrote a side by side comparison based off of the numbers Mike B gave and the difference between 1 low through 3 high are so small in both high and low range the difference is less than 1 mph per gear shift. From 4 low up there is quite a difference assuming I shift at 3200 rpm in all scenarios (on paper). The power the 427 has as 78buckshot said is quite high. I don't see me having a problem. If I do i can just put the 5756B back into it. I also have a set of 5:29 gears sitting in my garage as an option too. A transmission change is faster than a hear swap.

Does anyone know what clutch the 3053A uses? Is there a spline size/count difference between the two transmissions? Are both bell housings the same enough to swap?

Edit: I have found for the specs for the 3053A input shaft. It is 10 spline 1-1/2". I am unable to locate the spline and size of my 5756B as of now.

Last edited by Pvmt-Pndr; 01/26/2021 4:44 PM.