I'm not a big fan of the mags BUT, if i had them on already, i wouldn't go to a J. Why? Because, i would loose compression, and a Quench pad is not a bad thing :thumrigh:
Depending on late/ early X casting or all J casting, the piston was different to fit the chamber shape. They were looking for 10:1.
If you've got flat tops and anything close to zero deck, you want tight gaskets and closed chambers.
The reason I would suggest Engine Quest heads, should you ever have to change or have cracks, etc., is because all of your current running gear will swap over and they have better quality casting.
Other than that, you'd gain more from RHS or Edelbrocks, but if you go that route, you'd still be better off with Indy's reworked Edelbrocks. The guide material sucks and CNC quality control is shaky, out of the box on the Edelbrocks.
If you're looking for more hammer, spend your money on a converter. If it's a street car, go with a Dynamic. If you like it loose all the time with a fair ratio and wanna save a little more, go with a Hughes.