I'm pondering a 445 build with my 390. It will be for a street car, 67 Mustang Convertible. I'ts a fairly standard build, 4.25 stroke. 10:1 comp, C6AE-R heads (or stock C7 GT heads) with CJ size valves, pocket port and good valve job. CJ intake, carb and exhaust manifolds with a 2-1/4 or 2-1/2 stock fitting exhaust. Transmission is a C6, (I'm collecting parts for a toploader conversion). The car has power brakes, AC, PS. It has a 3:0 open differential now. I plan on changing to a 3.25:1 trac-loc.
It seems like with this combination, the biggest consideration regarding cam selection is to end up with a responsive engine that revs well from 1,500RPM to as close to 6,000RPM as possible and holds good vacuum at low RPM for the brakes, automatic transmission, etc...
I am thinking about using a solid lifter cam like the 282s from comp. Any cam specs to consider for vacuum? I've read that for good vacuum, staying below 220 exhaust duration at .05 lift is a good rule of thumb, but I'm not sure if this holds as the cubic inches grow.
Does anyone have experience with a similar build and resulting vacuum? Ideally I'll end up with a very responsive fun ride with vacuum enough for the brakes, automatic transmission, etc...