[Sirrotica]

Originally Posted by Tom Vaught

Never saw that at the Pontiac dealership.
Course the engines that were 2 BBL 389 engines and early 400 engines probably already had the later 60 psi pumps installed due to the oil pump screens and pumps being plugged with NYLON timing gear material when the gears failed and plugged the original 40 psi oil pumps.

Tom V.

Since I've been working on Pontiacs since I was 15 YO, I might have seen the inside of a lot more 389s and 400s than someone working in a dealership. When I worked for myself 1977-1982, I specialized in Pontiacs at my garage/ gas station, and probably worked on 50% of my customers were Pontiac owners. I also worked for a brief time in 1970 for the local Pontiac dealership while I was on Co-op from the Vo tech I graduated from. Plus raced them at the local dirt track, and also auto crossed them at local SCCA events.

I actually had some of the people that worked at the local Pontiac dealership bring their cars to me for work on their personal cars, The parts manager lived close to my business, and he sent other employees to me for service work.

I used to have a parts manual that the parts manager gave me when they sent him a new one. It was inadvertently tossed somewhere along the line, and I can't look up the parts any longer, so I'm operating on recollection many times when referencing what came on what engines. It's not 100% accurate every time, but I attempt to make posts as accurate as possible on PY.

Perhaps someone that still posses a parts manual can confirm, or deny that fact. I know that at 70, my memory isn't as good as it once was, been wrong before, and I'll be wrong again. I'm fairly certain though I've taken the small diameter pumps out of engines later than 1960, but they were low performance 2 bbl engines.

From Rocky Rotellas Pontiac engine article about Melling 54 standard pressure, 5/8 inch pickup tube, 40 PSI oil pumps:

Melling began manufacturing its M-54-series oil pumps for Pontiac V-8s in 1963. “The original No. M-54, which was our standard-volume pump, rated at approximately 40 psi, was discontinued around 1990,” says Osterhau

Same article covering the three distinct oil pumps Pontiac used:

Pontiac used three distinct oil pumps in its V-8 engines, and they are often referred to by approximate maximum pressure ratings of 40, 60, and 80 pounds per square inch (psi). The 40-psi unit is the easiest to distinguish by its 5⁄8-inch-diameter inlet opening, and it was commonly used in two-barrel and low-performance four-barrel applications

If the use stopped in late 50s early 60s, Melling would have produced them until 1990, just my own thoughts. Those statements correlate what I remember about disassembling, and building them, dozens upon dozens of Pontiac V8s from a 1956 317 CI, up to 1981 301 engines. Just my recollections here.