check fuel pressure as denny described... check volume, i'll check mitchell tomarrow for you to give you specs on how many ounces per second, also when checking pressure, turn the key on for when the pump does its initial prime of the fuel system, should spike up a bit, and then stabilize, if it drops back down, you've got a bad check valve in the fuel pump, very common problem that a lot of techs overlook.... if all that seems to check out then its probably a dirty tank..... also if your system has a little vacuum can hooked up to the fuel line, you could try disconnecting the vacuum hose and plugging it, should bring fuel pressure up a little and see if it still stalls on hills.... that'll then tell you you're not getting enough pressure