[rideblue00]

CRGRS66 beat me to it, lol. Yeah the big hump you would know if you have it. The hump you have under your seat there...its the same on all trucks. Its the part of the floor thats in front of that. A 4 speed truck floor, is way taller between the firewall and the seat. Powerglide and 3 speed trucks have your floor. The 66 year had the turbo 400 availible and it also has the same floor as yours. I dont have a pic handy. But i have a big hump with a 4 speed SM420 trans. 4 speed floors are also removable. There is a legend out there about the early trucks that had a removable small hump, but i havent seen pics of it. Im not sure on the fit of the newer trans, but the 700r4 supposedly just bumps the floor pan seam that runs side to side, like where your feet go, and some guys just peen it over near where it touches.