The engine is out, and on a stand. It's a 150 dollar engine. I'm going to clean the jackets, level it and fill it from the deck, slap it back together and see how much it will take.

Are you gonna street drive it.. if not then go
higher on the fill

Yes. I'm thinking just lower then the water pump holes, will be fine.

What radiators are your guys running that have half block fills?? I have only a 22" rad support, I want to run a 7 blade clutch fan

That will be about a 3/4 fill.

Guys is it worth also installing the steam vent lines from the back of the head/inlet manifold to the t/s housing on these half filled blocks? I have w2 closed chamber heads with a victor manifold

Never seen my water temp over 190. Remember, if you are replacing 2/3 of the water with hard block, whats left goes through the rad 3 times as often as before. Oil temp goes up, water temp goes down.

Crizila,you see in any crazy oil temps with it filled that high?

Oil temps are up for sure, but still well within the operating range of the oil I run - at the track. As I said, I have no experience over long periods of time on the street in hot weather. Half fill, you may have to go with an oil cooler. You will just have to try it and see.