Here's the deal:

All stock inline 200 Ford -- was the Falcon engine, but was also used in Mustangs; in particular, my wife's 67.

Symptoms: Once the engine reaches operating temp, if you switch it off and let it sit about ten minutes, it's hard to start and prone to going dead until you get moving down the road again. Pretty much a function of the heat rising into the carb (I'm thinking) and causing vapor-lock styled problems. Steel lines run from the gas tank to the carb, so the old standby of a "clothes pin on the fuel line" is no help.

All surrounding components are new or freshly rebuilt. I didn't notice this behavior until this past summer. Then I narrowed it down to the heat problem under the hood.

Possible cause: the original carb base plate has a water jacket pass-through. When I rebuilt the engine, I found a leaking crack in the base plate and just bypassed it with a heater hose. My assumption was that the water pass-through was for pre-heating in cold weather and not all that important here in the Deep South. But now I'm thinking, maybe it has a *cooling* funtion as well. I thought about a malfunctioning choke, but this seems unlikely; then again, I'm not much of a carb man.

Anyone else run into this before?