The blacktop has lighter internals which happen to be also weaker, but it is a bit more rapidly. No harm if you're not accomplishing any huge mods, but any pressured induction and you will be needing to uprate the blacktops internals. Excellent automobile products and solutions and wonderful customer care. https://beckettlnonm.activablog.com/26494977/detailed-notes-on-4age-20v-blacktop-for-sale