I've torn down my 327/ 350 HP out of my 68 vette. Ran poorly before teardown. Engine has 109,000 miles.

First question is regading the valves. There is no evidence of valve stem seals. Engine was smoking and burning oil. Did someone leave them out when a valve job was done, or could they have disintegrated? Only have a small O ring seal on valve stem near top of valve.

Second question regards running pump gas. Had been running premium plus Octane booster plus lead substitue. Last tank last fall contained ethanol.

I'm replacing rings and bearings along with new valves, seats and cam.

Anybody have recommendations for what Gas is available for 11:1 compression engine?

Thanks for your help