I just bought a reman 302 long block, it has never been run and I want to change the heads. can I used the head gaskets that are on it or should I change them.
Agreed, the gasket has already been compressed. Once compressed you don't really need to re-use them, you (could) re-use it but you will not get as good of a seal as a new gasket will give.
No point in reusing them. Just asking for trouble. Go with the 9333pt1 like grn92lx suggested, I believe they are 15 bucks each and your local parts store should have them in stock.
I will thrid those gaskets. I've running them on my 331 with 8lbs boost with head bolts - no problems. I know one place that uses them on 9 sec turbo cars so they will hold up.
X7 on getting new gaskets. Remember your going to have to follow the torque sequence when tightening the heads down and you'll have different torque values for the bolts that you use sealant on versus the ones you use oil or assembly lube on.
I've never had a problem with just using motor oil on the bolts and I've had the heads off a bunch of times, never got a milkshake in the pan from not using sealer