Back a few years ago, NHRA allowed the Stock eliminators to run the R/T heads. The were worth about 2ths of a seconds on ET, but they added 6 HP to your factor. It really wasn't worth is because we saw no real changes in our ET.
I can believe this. The castings on mine were ultra-rough and the guide bosses were huge out of the box. I really believe a stock Magnum head would outflow them AS CAST. After porting though, they were beasts. LOTS of metal removal!!
