Notched my first piston "pics"

you have to notch them to use e7 heads. the cam is a stock ho cam out of a 94 stang

No you dont. I had a 88' Ranger that I used a stock crown vic 5.0 and dumped the E6's for a set of stock E7's AND used the stock H.O cam to boot. Anything more and you would need to notch them but there would be no way I would notch a non-forged mill in favor of a bigger cam, just me.
 
I totally agree. But I don't know if I would used a set of used pistons from another motor in a different block ........and if someone has done this please let me know the outcome because I have an old vic motor and a set of old forged slugs I could build for my sons LX 4 hitter.

The piston should not "wear into" the bore. The bigger concern is the ring lands being fubar from age. If they measure out ok, and you can clean them up good enough to look for cracks and such, then there is no reason you can't use a used piston.


Mic them, inspect them, and if they are ok use them.