I've got a little bit of smoke on startup not black just a lil grey. Car seems to be running fine other than that.
Any ideas?

 

yup...one or more Cylinder ring(s) are gone bad.When the engine is hot the ring expand making it harder for the smoke to come out. When the ring(s) is/are cold they contract and making it easier to smoke to come out. If it gets worse then you will develop oil burning....NOT GOOD.I recommend getting heavier oil.

 

I would check your valve seals before thinking it's the rings. My car did the same thing, I pulled the heads and repalced them with vette heads, no more smoke. The bores were fine, and I had normal compression. A lot of GM's had this problem, it's those stupid rubber o-rings I think??

 

On a SBC 95% of the time if there is any smoke at startup it is caused by valve guide seals. Chevy just didnt design them very well, and they fail often. They can be replaced without taking the heads off, its real easy if you have compressed air. There is a chance that your smoke could be caused by bad rings, but you would see smoke during engine operation, not just at startup.
peace