Newbie needs help with 20" wheels and lowering 71

[*hotrods*]

Hey guys I'm new here and would like to get some advise on wheels. I have a 71 Cheyenne swb fleetside bbc truck that I recently bought. I'm considering going with a 4/6 drop and want to run 20" Vintec's. I have read several post and even done a search but can't get exactly what info I need. I want to tuck as much tire and wheel as I can on the rear and front but want to stick to a 40 or 45 series on rear and maybe 35 series tires on the front to give it a nice rake. I have seen were guys are running 20X10 with a 5 1/4"bs and a 295/40/20 and 20X8.5 with 4 1/2" bs with a 235/40/20 tires. The rear seems a little wide and I'm not sure if they won't rub.

I need help on this bad guys!! I want as much dish also on the rear, so if some of you 20" guys could give me some advise and show me some photo's it would be geatly appreciated. Also any advise on the drop would also be appreciated!!