I used 400 then 800 and finished with a lite sanding of 1200 grit. Bought a set of polishing buffer wheels and bars of polish in a kit off ebay for $92.00 bucks and a cheap polisher from Harbor Freight for $50.00 bucks.
Time to sand roughly 3.5 hrs per tank, time to polish 2 hrs per tank. I have plenty of polish and buffer wheels are in good shape to be able to polish some other things too. Polisher speed 3,500 rpm.
Hooked up air compressor to dryer, fuel system, power steering hydraulics and built belly strap/brace under transmission. And set radiator plus hooking up cooling hoses now.
Will install headlight buckets and lights plus run wiring.