I should have mentioned that this is in my 1970 El Camino with a 350 sbc. I need to update my profile. The 37 has been gone for a long time.
Glenn, contrary to your advice, I removed the stock radiator, fan and clutch and installed the 3 row aluminum radiator with the dual fans. Doing this dropped the temp 10-15 degrees but this drop in rpm is something that I don't like. I'll try to identify this alternator set up before I do anything else.