[jayboyz28]

I am a mechanic in Windsor, Ontario, Canada. I have a customer with a 1967 Firebird with the OHC Sprint motor in it.
About a year ago, he was driving the car home from a show and it began to huff blue smoke out the tailpipes when leaving a stop. Doesn't seem to blow smoke while driving, but it might be. He brought to me and ask me to do valve seals. After pulling the cam carrier off and removing a few valve springs, it was determined the head needed to come off as the valve to guide clearance was too big. Sent the head to the machine shop and after lots of waiting, finally found new valves for it and got the head back and installed.
Customer took it and brought it back, still smoking.
Ended up pulling the engine and doing a full rebuild on it. New pistons, rings, bearings, etc.

Believe it or not, still huffs blue smoke when leaving stops, but only after it is fully warmed up. Will not smoke when cold.
The intake valve to stem clearnace is 0.0016 and exhaust is 0.0024. We have positive valve seals on the intake valves, but just the oring seals for the exhaust. When I pulled the exhaust manifold off, the exhaust ports are full of oil. We are lost. PCV systems seems to working properly. So we are at a point to put positive seals on the exhaust valves too. Seems most people I have talked to have done this. Do you use positive seals on intake and exhaust? If so, do you have part numbers for the seals you use?
Any help would be greatly appreciated.