[BR3W CITY]

Only stays running under heavy throttle and dies on a stop?
The only running wide open part suggests either a vacuum leak, or a problem with the MAF.

Dying on a stop can be a few things; if you don't have tank baffles and were low on gas, then the engine might have just starved. A full tank will reduce the problem, but getting some tank foam or baffles should stop it.

Vacuum leak is still plausible, as the brakes require a deal of vacuum, and with a big lopey cam, its not unheard of to stall out of die under heavy braking (hence the use of hydroboost or vac cannistor).

Last option could be the lockup if your running an auto; I was just dealing with some problems regarding lockup and big cammed auto's; the solution involved the misfire count from the cam, causing erratic lock and unlock.. Staying locked up on decel can "bog" the engine and stall it out for a second. Sometimes its not even a "full" stall, it will drop to 1rpm, not throw lights and then pop all the way back up to 790 at idle.