1988 98 regency brougham problems

i just got an olds 98 from my dad... he got it from some guy who said it was overheating and stalling... the guy told him that after 25 miles it would die and would have to cool to start again... we replaced the ignition control module and thought the problem was solved... it ran great for an 80 mile trip, but then it started stalling... it doesn't stall at any specific interval... sometimes it runs great all day, and other times it stalls after only driving a short time... when it first started stalling it would make a "gurgling" noise on the left side and then it would start again... dad suggested moisture in the gas or a clogged fuel line, so after some gas treatment, i tried it out again... it worked great for a day and then the stalling started back up... sometimes after it stalls it takes a few tries to get it started again, other times it cranks right back up... the gurgling noise has now apparently been replaced with a grinding motor type sound shortly before the car will start again... i am thinking it is possibly the fuel pump, but would like a second opinion... thanks