I've got a 235 in my 53 with a Rochester single. it has never ran like I think it should. got it to where it starts great, idles good. it will set there and idle good till the cows come home. so I go for a cruise, maybe 10 minutes at 50 mph. pull up to a stop sign and it won't idle and quits. if I get it started I have to keep the engine running at a pretty high rpm or it will die. some times I get it home park it and it'll set there and idle beautifully (sometimes not) but if I walk away from it and come back later it starts right up and we go through the same scenario. I've cleaned the gas tank/lines, replaced the fuel pump had the carb apart a half dozen times. Float level is at 11/8 closed and 11/2 drop (to spec I think). needle vale seem to shut off the fuel, at least statically.
I've changed plugs, set the timing, adjusted the valves and replaced the coil resister with an internal resisted coil.

To me it seems like a flooding issue, but i'm hesitant to go back into the carb unless I know what i'm looking for..about at wits end !!

Any idea's