Due to dissimilar metals and the corrcosion that can occur in electrcical circuits do to that I would install it onto the block and not the heads Maybe ground the motor to the frame off of the bottom 7/16 bellhousing bolts, the ones on the bottom ears
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Maybe ground the motor to the frame off of the bottom 7/16 bellhousing bolts, the ones on the bottom ears 
