Glad you figured it out. Years ago I dailied an 87 Diplomat cop car. It had all the cop stuff with a very gutless Lean Burn 318LA engine. On one of the fender supports was a cooler. Fed by the oil pressure switch then dumped into the front fuel pump mounting bolt. Yup, hollow.
And hey, I got a regular with a 68 Fairlane. 800k on the clock. Did the timing cain a few years back on that 302. and it had the toilet paper oil filter and in the 13 years I have known him, he has never once changed his oil. Only his *** wipe.