I removed the passenger side valve cover today. This is what was on the head. GM 3T on the left side PASS in the middle and 8272292 on the right side. Are these Oval Port? Are they decent factory heads? Also I'm having trouble getting the wrench around the bolt closest to the distributor cap, it's like there is no room to work without hitting the valve cover, Should I get the wing nut type bolt with the long rod to make it easier instead of regular bolts?

I think if you look closer you'll find that first number is a "6". If so...

6272292 1971 402 240, LS-3
454 Open 270, LS-5

2.06 intake, 1.72 exhaust. Open chamber, aka "cereal bowls". They flow okay, but you'd need a piston with a little dome to get compression up.

Thanks for the reply, Yes your right about the first number being a "6", it was getting dark when I looked at the cast #. Sorry to be redundant but are these oval port? I'm not sure if I'm going to change the pistons right now, do you think I could still make some good horsepower gains with a new intake and some headers?

Yes, they are oval ports. Save this link for future reference.
www.mortec.com

Thanks!