Fender flares
I went back and looked at more of your progress. I saw where you cut the rear fenders. Did you do anything to close the void between the inner and outer fenders?
I went with a Gear vendor O/D unit as well. I have a 350 with an edelbrock 122 e-force supercharger, headers, water/methanol injection. 315/75/16 tires, 410 gears, FF 14 bolt rear,end, 4" lift spring all round.
I think I am indicating about 5 mph slow right now, but at approximately 65 mph I am turning between 2200 and 2500 rpms. I had the transmission rebuilt and they installed 2000 rpm stall converter so it turns a little higher than before.