I run 155x15in metric radials[vw] on front with centerline 4x15 in wheels with all the offset to the outside,gives me decent clearance and never had a heat issue with 2" hooker supercomps fenderwell,turns fully and no rubbing,could go with a taller tire no prob...and these headers will more than support 600+ hp...you could also wrap the headers for insulating values if you needed too,structural integrity is not an issue and they look and sound bad ***,I like them,car not currentely going but am getting another 440 ready for the street,also frame tied,narrowed rear and ss springs relocated 4" in,took out gas tank for ease of 3" exhausts to run to rear of car[alum 10 gallon fuel cell in trunk] in a 71 dart swinger...easiest headers you will ever r&r..I also relocated the MC and lines and will probably add a heat shield there but heat dissapation seems pretty quik,plugs are a snap,I also run copper exh gaskets...just my experience with mine,lucky I suppose...mine was also a /6 car and run the schumaker mounts...wouldnt change a thing