273 carb probs!!!
Hey Rick I am not a big fan of Holleys but since the only eddy I could find was a 500 cfm I tried the 390. Holley has a great website that explained how they work with vacuum secondary's. They are saying you should not feel a kick that they should only open when manifold pressure requires it so a 600 will not open or should not open until it is needed which on a stock small block it will be screaming, a stock tranny will shift before then so top end is the only time this will happen.So that said it makes sense that the fuel in the secondary bowl will dry up and refill before you ever use it in every day driving so going smaller make sense and still looks good when you open the hood. Mine starts great cold and very short term after shut down. I can smell fuel after shut down that is why I think I have a fuel boiling problem flooding engine very hard to start if it sits or 5 10 min. they make a spacer for this which I am going to try next season. Wow that was long winded lol.
Check Holley web site good info.