Camshaft + converter for 318 w/302 heads

I am instling a 1985 model 318 with 302 cylinder heads into my 1972 Duster. The engine has low miles and the heads are in great condition, with new guides installed. I need to know what camshaft I need to run in it. I bracket race it only, so I need a camshaft for maximum rpm that these stock heads will work best with. Will milling the heads help any and will it affect my valve clearance with stock piztons? I have a 318 Streetmaster and a Performer intake to choose from. I am running 3.55 gears and my Duster weighs 2800 lbs. I have a new Mopar purple cam 280 .474". Will it work well with the 302 heads? What about a torque converter for this combo? Are the 302 heads worth porting? Thanks.