If you want more torque,just turn up the boost.
My Syclone dynoed @ 550 ft lbs of torque @ 3000 RPM,21 psi @ the wheels.

Personally,I would run the 4200,it will fit better than a 292,lighter weight & will make more power.Better on fuel,they look good to me.

According to EFI diy the head flows as good as my Kirby head.


MBHD


12 port SDS EFI