small block V8!!!!

We have a pasture with several cars in it 12-15 fords, chevys and chryslers..my dad said i can have whatever i want out there...anyways i took a th350 and a 5.7 v8 out of a 1970 pickup..im selling the th350 and i plan to build the v8 to put in my car. im shooting for 350 Hp. the engine was alittle froze but its alright now...i took the heads off and the cylinders look mirror smooth....now to the question
the pistons dont look like 1970 pistons they look like a modern style...it has 4 valve reliefs ( im guessing) anyway all the pistons are marked with a "J" right in the middle of the piston....what does that mean? and are these stock or aftermarket pistons? how do i tell?
i will get pics later

Http://www.summitracing.com
part number TRW-L2256F40
it kinda looks like that....except with a ridge along the top edge of the piston () and not as shiny lol

Damn dude, I was checking out your car domain and all I can say is ou turned that car around dude.. it looked like a peice before, especially with those rims, wtf were they thinking?!

I wouldn't worry about the pistons, cuz I'd replace them with some keith blacks or something. pistons themselves are fairly inexpensive.

Thanks alot man..people that do that to cars need shot...Remember "Some people are only alive cause its illegal to kill 'em"
I think he is high all the time...i would like to get that guy in front of a huge electro-magnet...that guys face is so full of metal .....lol
btw i dont have the pistons out of the cylinders yet..i think the cylinders are standard bore

yeah i know..one of the cylinders look a little rough i need to bore it so i need new pistons anyway

ok i got the other head off...heres the weird part..all the pistons dont have the "j" stamped into them on this side...one has a bulls-eye marking on it and the rest have either a J,K or H stamped on it.....also the exhaust valve on the back rh cylinder has a chunk missing but no visible signs to the piston or cylinder