Building a 400 small block for my Dad to put in his 55 Bel air. Want is streetable with some good torque for fun on the street. Running a manual transmission with approx 3.50-3.73: rear gear.

Block is .030. Stock crank turned .010. Stock rods with APR bolts. Pistons give about 9.5:1 with stock 76cc 400 head. Cam is hydraulic and mild to moderate trying keep it a torque motor. With 406 CID Question is how well do these stock heads work and what mods are necessary to use them. Already have 2.02/1.60 manly valves to have installed but what if any porting should be accomplished?

Or should I just trash these heads and buy something new. I am open to suggestion on buying new, but pistons purchased already yeild about 9.5:1 (sealed power stated 9.7:1 to be exact)and wanna keep this motor on pump gas and reliable. Most after market heads arent offered at 76 cc form what I have seen. (yes know I have to have steam holes drilled for 400) Want to give the old man just one last good solid car to have fun with. He's 59 now and drives a vette but still talks about his 1st new car at 21 which was a 65 GTO with 389 and 3x2s so want to help give him another rod to have fun with.