Which way should I go with pinion angle ??????????????????????

I got another driveshaft today. It will need to be shortened a little but I had just enough room to wiggle it in to get a good visual of what everyone is saying. I got it now. Since the trans is at 0* and the rearend is 4* nose up, I would have to use way too much shim to get it turned to where it needs to be. So. I am going to pull the rearend and cut the perches off and have some new ones welded on at the correct angle.

Now here is the big question. For a street car that will probably never exceed 400hp, how much pinion angle will I need? It will be fairly simple since the trans is at 0*. I know it will need to be anywhere from 2*-7* nose down at the pinion. 2* seems like not enough, but 7* seems too much. To me 4*-5* nose down seems close. Any more than that and I don't think the axle would ever wind up enough to use 7*. What do you think?