If it's Lucas, it needs an incoming speed signal - mine used to stall a lot, I was convinced I had some kind of vac problem, but once I replaced the speedo cable that had recently broken, hey presto, all was well!
So, before you go changing your vac hoses, idle air control valve, AMM etc etc, does your speedo work?
Failing that, I too would start by replacing the vac hoses.