Both are that of hand-me-downs from the aerospace community. RedLine and Royal purple. Although, Mobile One is another good choise.
I have done a lot of engine development with Jim Jones at Traco engineering, for a streeter, Mobile One. Because you can purchase this stuff anywhere, at anytime. Now for a race car, or something you just want to squeeze every inch of power and relyability out of (or just baby) RedLine or Royal Purple. The only difference is about $2.00 more for the Royal Purple.
Between Mobile and RedLine, after about 20,000 miles (race) we saw absolutly no upper valvestem wear with the RedLine as compared to Mobile One.
Between RedLine and Royal Purple, I took 12 cars to the chassis dyno, ran them all, randomly selected 6 cars, changed to oil to Royal Purple and found on average about 12-15 hp gain with the Purple.
Then again, its only money. How fast do you want to go?
[This message has been edited by chacane67 (edited 01-11-2001).]