1972 318, coolant getting into oil

Yup I've had (too many) timing covers fail like that. Mostly magnum engines but not all. Most recently was the 3.9 in my Dakota. That one had had the timing cover gasket replaced at 91k before I got the truck, it went again on me about 125k.and the cover was pitted bad enough that ti wouldn't have sealed with just a new gasket,or not for very long anyway.i wound up replacing the cover.and unlike the overpriced idiots that did the job for the po,
I replaced the timing chain set while I had it exposed.
IDK why but every time I see this problem it blows on the passenger side right behind the alternator, up high on the cover.