I found a really nice 88 F-150 for 1500.00, i noticed as i was driving it, the oil pressure gauge was in the normal range but on the low side of the normal range, didnt hear any unusual noise, but i was planning on replacing the pump and screen and see if this didnt clear up, there are so many brand and options to it, what type of pump do i need to buy, standard, high volume or high pressure, and what brand, i can get a original from ford but its 110.00, someone please send me in the right direction, thank you

 

Regardless of what anybody else says, you DO NOT need anything besides a standard volume and standard pressure pump. The standard pump is even plenty good for most performance applications and definitely more than adequate for a stocker. Ford Racing sells a standard volume standard pressure stocker pump and the price is very attractive. The part# is M-6600-M50. It's the exact same piece that went out on production engines. Summit Racing sells it for about $25. I just bought one on eBay for under $10! The seller still has more. Check it out here

FORD RACING 289 302 STANDART VOLUME OIL PUMP PUMPS: eBay Motors (item 220657425543 end time Aug-27-10 06:32:23 PDT)

Now with that said, I wouldn't be in a real big hurry to tear the oil pan off and start swapping parts. The oil pressure guage in many of the trucks off this vintage is misleading. What you are looking at in the dash is a bona fide oil pressure guage, but it isn't operated by a varistor-type sender to give you accurate oil pressure information like they were in the good old days. It has a regular low pressure switch screwed into the engine and there is a resistor in the signal wire to the guage that is calibrated to make the guage read about mid-scale. You either show mid-scale or nothing. It's basically a glorified idiot light and its readings should not be taken literally. Before you do anything else, go get a mechanical oil pressure guage and rig it up for a few days. If you are still showing low pressure, then it might be time to start looking for the source.

My experience has been that the oil pump rarely is the source of low oil pressure problems. It usually comes back to worn main bearings or worn cam bearings.