TRADE: Pro Topline Vortec Heads

[Fast355]

I don't know of any 64cc tbi heads made may wanna look for some L98 tpi heads

ALL 350 TBI heads are in the 64-66cc range. The difference between the 8600+ GVW trucks is an 18cc dished piston vs a 12cc dished piston.

If you go with TPI heads, you will have the same compression ratio and less torque than the swirl ports. About the only thing that can be done is mill/angle mill the heads and intake and us a .016" compressed steel shim headgasket or change the pistons.