[asphaltgambler]

I'm a big chevy guy - had LOT's of experience over the last 35 years. My opinion. The 305 stock or modified is a boat anchor, period. Unless you REALLY want to rebuild it yourself, you'll do much better dollar-wise and time-wise by buying a complete running package - OR long block and purchase the correct carb/manifold style and size and jet it according to the engine builders recc's

There are soooooo many waaaaaaaaay better choices like this than to re-bop a 305 which, by the way, GM was short-changing the amount and actual quality of the steel in the block and cyl head castings at that time. If you do the build properly with that much mileage - plan on replacing every moving part - or you'll pay for it later.

Example: If you had a machine shop completely (and correctly) refurbish those heads including all machine work, parts and labor - you could buy a set of Edlebrock aluminum street heads complete. Technology and manufacturing has come such a long way that rebuilding an engine of that era is pointless. To that end many machine shops I have known are either out of business OR are frantically looking to laterally move their equipment and talent in a new direction