I'm trying to decide on a set of heads for my 1974 Chevy 350 w/ 4 bolt mains. I'm having trouble getting straight answers from manufacturers and suppliers. Maybe somebody here can answer some of my questions.

They offer some of these aftermarket heads with the valves at different angles. What's the advantage? I am running flat-top speed-pro pistons with Fel-pro gaskets.... what do you think I need? 14*, 23*, 18*, etc?

why do nearly all of them say that they need the edelbrock Victor Jr. intake or similar? I plan on running an offenhauser single plane, what's the difference?

Why does it seem that none of them are able to run stock length valves? Why do they all need +.001 valves?

any shed light on the topic is appreciated.