360 Magnum building on an existing bottom end

408 swinger said

At the vey least, check the upper rod shells. On account of the plenum plate under the intake, the Magnums detonate by pulling oil into the intake charge. Almost every Magnum I've torn apart, the uppers show a little copper because of this. Crank is usually OK with a polish.

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I also found this with the high-mileage 5.9 I pulled from the yard. Replaced the rod bearings, left everything else as-is and bolted on all my power parts; still runs great after 8,000+ miles. I also agree with @318willrun on checking the cam bearings, mine looked pretty bad but I was too lazy/cheap to change them out. Nothing to lose sleep over as like I said mine runs great but "while you're in there" and all that...

@65TTCuda check your block, if there is a passage drilled on each bank going from the cam up to the deck surface you can just bolt on and use LA heads (stock or aftermarket) and intake manifold, factory rockers as well if you please. If the passages aren't drilled you could still use LA-based heads but you'll need to use rockers that oil through the pushrods or plumb some type of external rocker oil feed, or have a machine shop drill the passages out. With the EQ heads no longer around there isn't really a good budget option for putting fresh heads on a Magnum. Might be more expensive overall but I'd go with some cheap bare aluminum heads like the Speedmasters and build them up to suit your combo.