I completely ruined a new set of 2 1/8" pro-parts headers to get them in my Demon with the 540 / 440-1. One big bash was to clear the snout bar on the tube that went through the inner fender. On the pass side I had to bash for torsion bar clearance and frame clearance. Besides the snout bar, the problems may be the motor plate locayting the engine a little off the stock location. I used a torch to heat the tubes and a socket on an extension which was the mandrel to make the dents rounder. Unlike that video, I tried to make the dents aerodynamic.
So the first time I took the car out to make some pulls and break in the new build it blew the good, metal core exhaust gasket at 5500 on the side that had the bash closest to the ex port, which was the one I bashed to clear the snout bar.
I don't know about that chebby which was making some nice numbers with that small cam not being affected. I have a lot more cam in the 540 and it didn't like the dents at all.
