Sorry if I missed it but is there any port and valve train work done on the heads? One mistake I see quite a few people make is going WAY to much cam on an engine that really cannot use it all [I even admit doing this back in H/S], of course it sounds wicked as hell, but is doggy down low, really starts to take off through the midrange, but then falls on its face because there is such a flow limitation through the heads, intake, and/or lack of carb, etc. Also, really good hardened roller rockers, hardened push rods, high quality lifters, springs, seals are all a part of the equation for the higher lift and duration cams and you want at least 110 lobe separation on the street and don't be at all afraid of 112.
Case in point, I started on my 442 big block build with a Mondello Twister JM-22-25-10 per their recommendation which is a 230/236 @ .050 274/280 advertised, .512/.523 Lift, 110 LS cam in an otherwise relatively mild 10:1 Olds Big Block with mildly ported Edelbrock heads, Performer intake, but only 750cfm on top and just W/Z exhaust manifolds [hate headers] into 2 1/2" dual. I found this cam to be low end lacking, pulled like a futher mucker from 2500 to about 5000 where it REALLY needed more carb and headers. Plus I also was wanting this to work with the factory CCC QJ and the ECM which had issues with this cam.
I changed to a JM-20-22 which is only a 224/234 @ .050, .496/.520 Lift, 112 LS and the thing is just fuel injection snappy, way more torque than I can possibly hook up with the factory suspension/wheels/tires [ALL changing as we speak], amazing power again up to about 5000rpm where the carb and no headers start to be problematic but I am grabbing the next gear at 5200 so right back into the meat. I am only running a 2400rpm HD TC into a heavily beefed 200-4R and 3.73s out back.
The nice thing is that the way the block was set up plus all forged and balanced rotating assembly combined with the way the heads were done will safely take this engine to 6000rpm easily and will flow enough to take this car to 550-600HP by preferably going to fuel injection, headers, and then more cam. So, if I find this thing actually does perform well enough auto-x and on the track to get the bug, I can make those changes without starting from scratch.
Given what you say you are looking for on a small block, I think something in the 215-225 @ .050 265-275 advertised, with .470-.480 lift and at least 110 LS [I would go 112] would get you some rumble at idle but with plenty of vacuum, very streetable, and the very snappy response you are looking for per your stated rpm range.
Hope this is helpful . . .
