Mopar Cylinder Heads Aluminum P4532900

From memory that number is the casting number for both the MP magnum aluninum and the MP small port commando as they share the same identical port layouts however the magnum version has 10 valve cover bolts and traditional magnum rockers etc. Out of the box they flow very poorly around 220 cfm on the intake as cast. However when ported they will flow side by side a edelbrock with similar amount of port work.
Their is quite alot of factory rejects sets on ebay currently but as long as all holes have been drilled and tapped they are usuable. However most of them seem to still need seats installed, cut and guides installed and honed. That alone will run arond $4-500.
RyanJ has done a few sets as not alot of guys seem to have touched them