possible 360 build

So if you have a complete engine, why not just go through it? Are the EQ heads salvageable? LA 360 and Mag 5.9 are balanced differently, is t
hat why you way to use the 360 rotating assembly or just because it has .030 pistons (which may or may not work)? What is the end goal?
I bought the EQ heads for the original build and they were built with too tight valve guides .
When I discovered a slurry of metal in the original engine that I rebuilt, I went and got another engine and dropped it in. I took the eq heads off figuring that I would get my money's worth out of them one way or another
so being as how I decided to replace all of the gaskets and freeze plugs in the 2nd engine anyway I wanted my new EQ heads on the Durango they were bought for. So the EQ heads are on the 2nd engine that I got for the durango, which my wife is driving daily.
I took the heads from that 2nd engine to the machine shop for checkout and discovered that they are cracked and were deemed junk by the same machine shop that I had fix those defective EQ heads.
Being as how I had a valve stick and kiss a piston, I don't want to take a chance on it being cracked from the collision with the valve
The Pistons in that motor are also new with 6 miles on them, 3 hours max run time/ they are also 30-over, like the ones from the LA engine. But the ones that are in the LA 360 are flat tops. Which the stock replacements in the magnum now are dished as the original stock ones were.
I'm gonna be buying new rings for which ever Pistons I put into the block, the flat tops are collecting dust and won't be used anyway so I thought I could make it a better engine with a little more compression by using the flat tops. They're here, might as well use them in something if I can.right?