Cool build I love magnum engines. I'm following! Love the color btw! Can I ask why your not using the heads? What are you gonna do with the original heads? And what are your plans for induction and cam?
I'm getting to that lol, it's kind of a long story... my old 360 had stock Magnum heads but they need a valve seat job and guide inserts before they're fit to work on another engine. Stock Magnum heads you get from the junkyard are almost always cracked and I already had a pair so I left them in the bed of the truck at the yard lol. Initially I planned to buy a pair of EngineQuest replacement iron Magnum heads and use those but then these open-chamber Edelbrock RPMs popped up on FB marketplace for a good price. I impulsively bought them before I realized they were LA heads and wouldn't get any rocker oiling from the Magnum block but trying to re-sell them was a waste of time so now I'm going all the way. Initial mockup showed they'll need to be milled on the intake side since they will definitely be milled at least .010" on the deck side for cleanup and straightening and the intake holes barely lined up as-is. The Edelbrocks are currently at the machine shop getting worked on and I don't know what the chamber volume comes out to but I doubt it's less than 63cc. With stock Magnum pistons down .050" in the hole and a .027" thick gasket (Cometic MLS) compression will come out to about 9.2:1. The Edelbrocks also came with a full head stud set, it's kind of begging to get a little boost heh heh...