IF you're blowing coolant out of your de-gas bottle and you have replaced your coolant cap($12 at any gm dealer) then yes you have headgasket problems
I've done it on my LBZ, it cost me $670 for grade-c gaskets and stock bolts, and took about 20 hours, but I had expert help, if you know a mechanic buddy or someone who is mechanically inclined I suggest doing it yourself, its a hell of a lot cheaper than a dealer
the choice was simple for me, $670 for the kit and do it myself, or $5000 to take it to a dealer... SCREW THE DEALER!!!!!!!
this is the kit I used > LLY Head Gasket Kit
you can select either stock bolts or ARP studs, I wasnt planning on running over 40psi boost so studs didn't seem worth the extra cash
Its a pain in the *** job to do, but its definitely worth it to do yourself, the GM time to do is 32 hours, so even if you do it in 40 hours its still cheaper to do yourself!!!