My rebuilt small block chevy has blue smoke on start up,runs fine.?

RedFish said

...
I dont think the problem is rings anyway since it only smokes at start up.
Probably valve guides and/or stem oil seals. If so it will suck oil through those on deceleration...

Click to expand...

That's it.

Maybe OP trusts us more than the Chevy guys, ever think of that?
So which A-Body are we talking about? Chevelle, ElCamino, Malibu?

At the end of the day, it's very poor forum etiquette to post a question without first posting an intro.