Engine Front Cover Assembly
Cadillac used this style from 1963 - 1967. No two are alike because of timing marks or filter adapter.
Oil Pump Specs and Info
The most critical part of this assembly is the oil pump, which is housed on the lower right portion. It is often overlooked because the attention is more on corrosion or a broken piece on the assembly. The oil pump has 2 steel gears whirling around in a machined figure 8 recess. Combination of steel gears and grit and debris in the oil can gawl out the aluminum sidewalls and the result is, despite replacing the gears, you'll never get good oil pressure due to the gap between gear and aluminum wall.
Cadillac factory specs are:
Tolerance between pump body and drive shaft
New limits................ .0010" - .0025"
Worn limits................. .005" (not over)
Tolerance between pump body and gears
New limits............................ .003" - .005"
Worn limits.................... .005" (not over)
To properly inspect, the distributor needs to be in place, because the shaft on the drive gear mates with the distributor shaft for support. The drive gear bore can be fret-worn, thus allowing some wobbling of the gear. When I used to inspect, I used 2 feeler gauges that were placed 180 degrees apart on the sidewall and being able to slide the tip of the feeler gauge up and down that gap. If the 2 gears and sidewall are out of tolerance, you won't get good oil pressure. You would be surprised how many people have called me over the years stating they had spent $2,500 or $3,000 having their engine rebuilt only to drive about 100 miles and the engine's fried because nobody paid attention to verifying the oil pump tolerances. Personally, I would add an oil pressure gauge to one of these cars