I've never had this problem and my macs have been on my car for over 6 years, the engine even overheated twice. I put in a fresh engine and the headers were perfectly straight and fine too
None, do gears instead. But if you must- go under-drive pulley.. although I felt zero difference with them on my 5.0 too, peeps say yo uactually make gains with them..
I've never had this problem and my macs have been on my car for over 6 years, the engine even overheated twice. I put in a fresh engine and the headers were perfectly straight and fine too