Stalling when slowing down to turn

I have an issue with my '88 speed density coupe. It is heavily modified (cam,heads,intake,etc) and runs awesome but has one issue. Now and then as I slow down to a stop to either pull into my driveway, or make a turn, it will stall. It idles & runs great, but I can't figure out the stalling issue. I want to eventually give the car to my son, but I don't want him killed because the car stalls as he trying to make a turn and he gets hit by oncoming traffic.

The car has the following mods and is still speed density:

Explorer Upper, Explorer Lower (Ported to Fel-Pro 1250), Thumper E7's w/GT-40 valves (Ported to Fel-Pro 1250), Comp Cams XE264HR cam, 65mm TB, 67mm EGR, 19lb injectors, Kirban AFPR, March Power & Amp Pulleys, K&N Filter, etc...

I'm not looking for "convert to mass air", I want to correct the stalling issue as it is the ONLY problem I am having.

HISSIN50 - I didn't check yet but from what I understand my car shouldn't have one because it doesn't have cruise control. Would adding one help? Is it even possible to add one?

jrichker - Great list! I'll check everything on it.

Thanks so much guys.

I'll have to check it when I go through "the surging idle checklist", but I was thinking that between braking AND turning it's using enough vacuum to stall the motor(?) I even thought about adding one of those vacuum reserve canisters. Any thoughts on that?

Looks like I have A LOT of things to check & test.