[1968GTO421]

I'm curious. Were any 428's built with the 40psi oil pimp or were they all 60psi oil pumps?

Thanks all!

[steve25]

Well at one time I had all 3 of the different 428s that where made and I can’t say for sure what was bolted to the pan rail for a pump.
That being said here’s the parts listing and it would seem that this is what took place.

1) in 1967 only the 376 hp 428 got the 60 psi pump.

2) in 1968 the 376 and the new 390 Hp 428 got the 60 lb pump.

3) in 1969 there was three different hp 428 motors offered and I would guess that out of all 3 of them that the 360 hp model did not have the 60 psi pump.

Maybe another member here here has a clearer recollection then I do on the subject and can make corrections on what I posted here, because I am trying to think back to 35 years ago here, lol!

One thing in hindsight that is clear now after however many motors have blown up, that all 3.250” main motors should have got the 60 psi pump.

[Goatracer1]

From Pontiac 1969 parts book: 67-68 P/8 exc HO or MT 428 9787517
67-68 P/8 MT 428 or HO 9787518
69 P/8 428 9787518 exc XE,XJ,YH,or YL engines
69 P/8 428 9787517 with XE,XJ,YH,YL engines
These are the oil pumps listed for the 428 engines in the dealer's parts book.

[HWYSTR455]

I've honestly never heard of a 40psi pump on a Pontiac V8. Not saying there isn't one, but just never heard of it.

.

[Bill Hanlon]

Pre '59 Pontiac V8 oil pumps were 40 PSI.

[HWYSTR455]

Ah, that's why I've never heard of it! Thank you!

.

[Tom Vaught]

Originally Posted by Bill Hanlon

Pre '59 Pontiac V8 oil pumps were 40 PSI.

agree.

Any 389/400/421/428 would have had the 60 PSI Oil Pump, STOCK.

The 455 SD Oil Pumps came "with a group of small parts" designed by Melling Tool Company (80 psi oil pressure spring, Higher pressure Longer oil "Spring Cup" but the same Oil Inlet Screen housing.)

The parts could be purchased at one time for under $10 to make the 60 psi pump a 80 psi pump.

Sold a lot of those parts to friends for use on their 455 engines.

Straight Shot aftermarket Cranks from Moldex Tool were a better "fix" vs the cross drilled cranks.

Tom V.

[Half-Inch Stud]

I've taken apart a apir of YK 390 HP 428s, and....basic pump with the typical larger 3/4" inlet pickup tube.

So, makes me wonder what motors had the Half-Inch pick up tubes? 350s?

[Sirrotica]

FWIW, the 2 bbl 389/400 engines up into the mid 60s, 70s used the smaller pump, with the small pickup tubes. Having converted more than a few 2bbl engine short blocks into a better configuration to be used in a high performance application. I used high compression, large valve heads, of course a new cam, full grooved main bearings, sometimes new rod bearings, depending how they looked upon examination then upgraded to a 60 PSI oil pump, and drive shaft.

The 400 engine in my 67 GTO race car in my signature pics, came out of a 68 Executive that I did that same conversion to. It had 88,000 miles on it when I pulled it from that wrecked Executive. The PO must have changed oil in it every 1000 miles, not even a slight sign of sludge in that engine. It lived a good life, won me more than a few races in the 2 years I had it, then when I sold the race car the engine went into a customers 68 Firebird street car.

I don't believe I ever saw a 428 from the factory with a 2 bbl, but in 72 there were some 455 2 bbl engines. I had one given to me in a 72 Catalina. It's been way too long for me to remember if that engine had a small oil pump, or not. Likely it did. A 455 strangled by a 2bbl, wasn't going top be a high revving engine. I always thought it was a weird combination, and it was only available for a year

A quick look on Wallace's Racing site showed no 2 bbl 428s, and 2 bbl 455 in only 72.

[Tom Vaught]

Originally Posted by Sirrotica

FWIW, the 2 bbl 389/400 engines up into the mid 60s, 70s used the smaller pump, with the small pickup tubes. Having converted more than a few 2bbl engine short blocks into a better configuration to be used in a high performance application. I used high compression, large valve heads, of course a new cam, full grooved main bearings, sometimes new rod bearings, depending how they looked upon examination then upgraded to a 60 PSI oil pump, and drive shaft.

The 400 engine in my 67 GTO race car in my signature pics, came out of a 68 Executive that I did that same conversion to. It had 88,000 miles on it when I pulled it from that wrecked Executive. The PO must have changed oil in it every 1000 miles, not even a slight sign of sludge in that engine. It lived a good life, won me more than a few races in the 2 years I had it, then when I sold the race car the engine went into a customers 68 Firebird street car.

I don't believe I ever saw a 428 from the factory with a 2 bbl, but in 72 there were some 455 2 bbl engines. I had one given to me in a 72 Catalina. It's been way too long for me to remember if that engine had a small oil pump, or not. Likely it did. A 455 strangled by a 2bbl, wasn't going top be a high revving engine. I always thought it was a weird combination, and it was only available for a year

A quick look on Wallace's Racing site showed no 2 bbl 428s, and 2 bbl 455 in only 72.

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.

[Formulas]

my 1970 350 2bbl 4 speed espirit had a 40 psi pump, I still have the spring and ball

i wouldnt run a 428 with a 40 pump it has a higher rpm potential over a 455 and obviously the large mains

[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.

[PunchT37]

They made a 2bbl 455 in `71 for the Bonneville. YB code, 280 hp. Wonder, even with the 2bbl with large main, did it come with the smaller pickup?

[Sirrotica]

Originally Posted by PunchT37

They made a 2bbl 455 in `71 for the Bonneville. YB code, 280 hp. Wonder, even with the 2bbl with large main, did it come with the smaller pickup?

Been too long, and I thought the one that was given to me was a 71, but Wallace site does also list 71 455 2 bbl. I must have missed it the first time I looked, so 2 years had 2 bbl 455s.

[Tom Vaught]

Oil Pumps (right from the Pontiac Parts Book):

59-63 All except 421 HO: Oil Pump 9787517 (40 psi oil pump)
64-66 T-8 (except GTO): Oil Pump 9787517 (40 psi oil pump)
67-F-8 - T8 Except 400 4BBL Oil Pump 9787517 (40 psi oil pump)

Oil Pumps 64 421 HO 486524 Oil Pump (60 PSI Oil Pumps below)
64-66 T-8 389 486524 Oil Pump
65 421 HO 486524 Oil Pump
65 TRI-POWER 486524 Oil Pump
66 421 HO 486524 Oil Pump
66 TRI-POWER 486524 Oil Pump

67 T8-F8 except 400 4BBL 9787517

67 T8-F8 400 4BBL 9787518 (60 PSI Oil Pump)

67-68 HO & MT 9787518 (60 PSI Oil Pump)

The 486524 Oil Pump was a 60 PSI oil pump
(Installed in all performance applications)

Tom V.

So I agree with the info from Rocky but right from the Pontiac Parts Manual

So the 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. All of the 486524 oil Pumps were for performance applications.

[Bill Hanlon]

Originally Posted by Sirrotica

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

The Melling M-54 (and I think M-54A) pumps were for 55-58 Pontiac V8 engines. The M-54 was a 40 PSI pump. I don't know about pressure the M-54A. Later pumps like the M-54D and its variants will not work in the 55-58 engines. The pump tries to occupy the same space as the crankshaft during part of the crank rotation.

I don't know if the M-54 would fit in a 389 or later Pontiac, but given the rarity of the early pump why would you try?

I just spent half an hour looking for a drawing I have showing the difference between 55-58 and 59 and later oil pump to block gaskets. I'll post it when I find it.

[Bill Hanlon]

Found the drawing posted here on our forum. The outer holes are bolt holes to mount the pump to the block. The center hole is the oil passage.
http://forums.maxperformanceinc.com/...2&d=1397610756

[Goatracer1]

T.V. can give you the part numbers and you believe him. I give you the part numbers and you ignore me. Thanks.

[Tom Vaught]

Let it go, not worth the typing to put the actual info in front of some people.

But I will say very few mistakes in the Parts Manuals (and Service manuals to a lesser degree).
They would constantly send out the latest CORRECT Information.

Tom V.

[Old Goat Racer]

Around 1980 I bought a 71 Catalina parts car for $100. It had a 455 with a 2-barrel carb YG code.