I drained my 83 Aspencade oil because it took some coolant, and the oil looked like bad coffee creamer (really) after 400 miles. Suspected a leak. Its a leak so small, but serious enough to do some harm, so both head gaskets were replaced, Plus Left Head. Still a small leak, and I got some old used oil, run it roughly 100 miles and back home, and I had to add another Near Quart of Coolant.
Still had a leak after checking it. So small it was impossible to see the Resivior Going down from the Coolant Resivior Tank.
I let it sit overnight, and it leaked down ablot about 1/4 of an inch. So tommowow, or a few days rest, I am going into the right side casting core plugs. So if you are getting oil contamination after doing the above, or if you replace a head, check and reseal these plugs. Life's a Wreck sometimes, LOL!
Check the casting core plugs under both camshafts. That will probably cure it. If it is, Just simply add some threading sealant like permatex sealer or silicone to the threads, and re-torque them. Problem many people overlook on an any wing that have them .