I see alot of conflicks on the subjects after 30 years into pontiac. with no kinda problems like i see on here.how ever i have found problems with machine shops. mostly overturned crankshafts-not checking valve stemlenth. On oil pressure the factory oil press is 30-40 psi @2000 on a brand new engine stock..but thats all proper crank specifications when you go to the machine shop if the engine builder cant give you main bearing clearnce-rod clearnce-shaft end play he did not ck it so do what i do take it home ck it your self.rod spec with feeler gauge and plastic gauge/the next oil pump from stock is a 60psi pump its why you see higher than normal oil pressure at start up but when hot its low. meaning to much clearence mains and rods and on rare times shop did not change cam bearings next the pump is a 80psi pump is the best pump to use the only thing wrong with high oil pressure is the filter will split. no seals to blo out..pontiac used this pump in 1973-74-455HO-and the normal oil pressure in stock 73-75 to 55-60psi@2000 in all sept the 455ho.th 80psi pump you still can get but you need the new oil pump drive to match and there hard to find. Rockers alighnment is another problem Pontiac made a tool to ck this alighnment a pontiac man i have one valve train gauge part#J-8928 and used with stud installer#J-8927 if you hade head work it probly was not cked. All the info factory manual..and some years of going behind someone to ck and see there work,,
The 80 lb. pump was used in Ram Air IV engines in '69 and '70 (production, Ram Air V also got it). Pontiac had a cadmium-plated distributor gear to try to "relieve" the problem of gear wear. The RAV and SD engines had the "factory fix" with the larger gear and smaller cam gear. 455HO engines all got the 60 lb. pump. Production on the REAL "HO" engines ended in '72. The '76 was an "HO" in NAME ONLY.
And you're right, lots of shops out there that cut corners.
Hot oil pressure is a function of the oil viscosity, the volume of oil being pumped and the rate of "leakage" (clearances) throughout the engine. To increase pressure, increase the first two and/or decrease the last one.
Using 25W-50 oil with a standard volume oil pump and loose clearances is similar to using 10W-30 oil with a standard pump with tight clearances or 10W-30 oil with a high volume pump and loose clearances. Using a high volume pump with loose clearances will use a slight bit more power but not enough to be of any significance on a street engine.
There are several ways to accomplish the same goal.
Use of a high pressure relief spring doesn't affect the hot oil pressure at idle. Excessively high pressure on cold start should be avoided by using the right relief spring.
