wheres the lowend tq...
With a good convertor your engine should never see 3500 rpm. It should be launching above that. As far as never seeing 500 hp with j heads, bullshot, I run 6.65 with j heads that I ported with no flow bench with .565 lift cam. J heads will make torque and horsepower but it is easier with a 360 to make torque. A stroke shaft would solve alot of your concerns. Loose weight from the car also. Helps 60 ft times alot.