Ok so for question1. ive seen some recent threads regarding it but not doing what mine does, so when i take my car out and get on it say strong 1-3rd it will go but when shifting from 2nd say i run it out up to 5500 rpm and shift into third, it backfires loudly, dont know what it is but its done it for awhile but there is no bog or sputter loss of power just sounds like uncle bucks car, if youve seen the movie. Question 2. id like to get heads really interested in the twisteds from trickflow, but how are the turbo swirls? are they good or is there a better ford racing head than those. idk the difference between those and like the gt40p, x, etc heads. i just saw the turbo swirls in mustangs unlimited for like 550 for the set and didnt know if they are worth it, or if i should just some extra cash needed for the trickflows and go that route.