[Bernie Cunningham]

OK. I'm probably a little biased here, but, Valvoline is the only oil manufacturer to have a RACE ONLY oil. What that means is, it has specific 'adder package' in the formula just for racing, it says on the bottle 'not for street use' and it's for real!
When the zinc content was reduced in most street oils a few years ago, (along with a bunch of flattened cams in race cars) Valvoline saw the need for a RACE ONLY oil, high zinc, low detergent etc. Flat tappet motors will benifit the most from this. I get really tired of listening to oil ads that try to compare ther synthtetic street oil to a conventional. All synthetic oil manufacturers buy their products from the same company it's all about how much of it they put in for their own 'blend'.
Don't believe the hype of a diesel oil as well. Yea, it does have a lot of the good stuff in it but it's designed for a max of 4000 RPM and as such, does not have the anti-foaming etc. for an 8000-9000 RPM race motor.
It's been proven on the dyno that a Valvoline, 5-30/10-30 conventional RACE ONLY oil will show better numbers, even against some synthetics !!!! Sure, if you want too, have your special 'go fast oil for class or heads-up racing' but put the reliable stuff right back in when ya done with that.
Valvoline Racing Oil is hard to find and a little costly but I don't believe it needs changing as often either, providing you don't have a lot of thinning from fuel blow-by, a smell test will tell ya.
Now the plug, stop by the Valvoline trailer on the midway to purchase (getcha some contingency decals as well) or you can buy it from JEGS online.