fuel inlet on the heads?
 

has there been any body machine the inlet to the fuel rail inside the head to a larger port? is the exhaust manifold to close to the port?

i drilled the fitting (but i had upgrades to steel #6 x 1/8 pipe ) to .250 that is what the bore in the head is from the top of the head to the fuel rail at the injectors. the brass . stock ones .180