Trying to build up a GRUNT 540

so far
540 (4.5 x 4.25)
10.2 CR
GMPP ( edelbrock) heads 2.25 /1.88, 320 CC ports
Weinad team G intake
two carbs ,750 or 1050 dominators
msd igniton

My problem is the area of cam seletion. My goal is a ton of torgue and let the HP fall were it will, maybe around 600HP / 650 FT lbs would be nice.
I would like to do this with a flat tappet cam since I dont plan on spinning it past 6500 RPM. THIS IS A STREET CAR ! no racing cams please

car...
3200 LBS
4 speed ( jerico)
3.91 gears.

Why don't you start out at something like a 290/240 high lift, solid cam b/c I have went through this D2K exercise with my 496 "tow-truck" motor when I settled on a good old CC 282S solid cam at 282/236 b/c your motor is bigger.

pdq67

PS., my about a 9.8 to 1 CR. 496 per D2K is like 551hp at 5500rpm and 579t at 4500rpm. To me, great grunt!!!