Ya, those aren't truck manifolds....that being said there was a member here that had those in a four wheel drive white truck (72 and up) and it didn't look that they had any issues with clearance and fitment.....they are like a small block...in that the donut is made to them....I kind of like that myself....if I was going to run manifolds I would try and run them......I've got both sets....but.....