I have a marine block in my '56 ..it was right rotation ..but I put my original crank in and everything else from the 1968 440...just used the block...had very low time on the motor and the bores were perfect ...still got the heads and intake and AFB .ecu..and some other stuff ...steel crank ..but have to have the rear maim nearling ground off.. Oh ..and the Marina cut it out with a chain saw..Paid $100.00 for it..