Ok, well.... my experiments with vapor-lock and fuel-capacity have taken yet another turn   I've got a 2003 tank from a wrecked LeMans with the internal fuel-pump on the way, and will be doing some testing with that. If it's in good enough shape, I'll probably just swap out my 2002 external-pump solution with the new one... which of course requires some wiring harness mods, but should solve the vapor-lock problem permanently     However, I am still curious how much fuel the 2003+ tanks