I had the head professionally rebuilt. Installed it. Starts and runs well until engine reaches normal operating temperature then blows blue smoke out the exhaust continually. Ideas?

 

Sounds like the rings may have not been seated properly.

 

There's a common theory that goes with older engines and valve jobs: Don't do them. At least that's what a few machinists I've talked to have said....

The new valve work will cause the valves to seal really nicely, increase the compression in the engine, and will cause the compression to blow past the old rings and cause them to wear. I'm guessing after your engine warms up, your valves seal and seat really nicely, and are putting too much stress on your rings. Might wanna get those pistons re-ringed, I hear there's a chance they might blow out completely.

 

WOW. So yeah, how many miles were on the motor when you pulled the head? Any history? Well maintained? Why did you pull the head in the first place? Have you run it for more than 10 minutes yet since it was put back together? Taken it around the block yet?