All the OEM iron BB heads except the Max wedge heads have that feature built into them to help reduce the heat from the cross over passage from the passenger side of the motor forced to the drivers side with stock exhaust manifolds to help heat up the intake manifolds shruggy
I don't think Mopar or any other of the car makers have that feature on any other motor confused

Last edited by Cab_Burge; 01/16/19 03:35 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)