'77 3/4 ton/ 1/2 ton parts interchange ??

[69runner]

New to the board so hopefully asking in the right place ...

I have a '77 3/4 ton long box chassis for use on a project. It has all the HD parts - 8-bolt wheels, duallie rear, etc.. I'd like to convert it to 5-bolt wheels. The rear end is a simple axle swap but what about the front end - can I just swap the rotors? Or what else needs to be swapped - rotors, caliper brackets, calipers, spindles ????

Thanks.