If you're talking about a pure stock drag racing engine, they really don't cost much more than a stock rebuild. I've checked them out and you can't run a 3 angle valve job from what I understand but I could be wrong here
I know a couple of people that run a stock engine class of racing. One of the guys dropped some coin on one of these so he could make sure his ignition system was working the exact way he wanted it to on ALL of the cylinders.