blykins: I use Valvoline in my FE. It was recommended to me by my engine builder (who advertises here). He recommends VR1 20w50 Racing, or the straight 50 weight VR1 during the summer (when temps are going to stay 70+). I just had the
oil changed from the 20-50 to the 50 a couple weeks ago, and the mechanic that did the change said that he probably would have stayed with the 20w50 year round, and that the 50 was too heavy (in his oppinion). The guy that did the change isn't my normal mechanic (he's on vacation), but he has a good reputation for being a top notch engine builder. ........Then again, so does the company that built my engine, and HE recommended the change to 50. He also told me to stay AWAY from the synthetics (???), which I thought was strange. He said it was too thin for the side oiler FE (which are prone to leak). When I heard "known for leaks" out of the guy that built my engine, I thought perhaps he should have spent a little more time on the build!
What do you guys think???