building 8 3/4 489 section

D go ahead and put 35 spline axles and spool in and be done. What pinion support do you have?
I don't know what pinion support it has. It is what was in it when I got it. I probably need to go to a lower gear also. It has 4.56 now and only crosses the finish line around 6400 rpm. It made peak hp at 7300 on the dyno.