A D1 has a copper / brass old school radiator. Rad shops can replace the fin material (re-core). Not cheap. For the PCVs, find your valve covers. There is a rubber hose that come out of each. Passenger side has a "oil separator" inside that can be cleaned with a few squirts of carb cleaner. Hose goes to engine intake. On driver side the hose has no separator, and goes into the throttle body. Clean out the hose and the port it goes into on throttle body with carb cleaner. And the throttle body butteryfly valve itself. Don't clean MAF sensor with carb cleaner. OK top remove IACV and clean with carn cleaner, just don't move the pintle around.

 

I think I paid $480 for my last heavy duty recor (so better than new), but worth it IMHO. I wasn't interested in an inferior radiator even if it was a lot cheaper. Good cooling is too critical.