I have a engine, a .030 455 with 6x heads. My friend has a 57 Chevy 150 with a 350 sbc...   he just ran a 14.87 in the quarter. He wants to improve on that. My question is l saw a 57 pontiac running a 455 getting into the mid 11 ' s And it weighed 4200 lbs.. Being that his 57 is only 3200 lbs. I think we may be on to something. The bodies look similar. Does anyone one on this forum have information on where we could find engine mounts and headers to fit this body style. 

You might start by comparing the engine mounts of a tri-five Pontiac Safari or Chieftain to '57 Chevy. I think the frames are nearly identical.

Next try getting a pair of Pontiac motor mounts. You probably can use the upper but you might have to fab the lower.

Chevy to Pontiac changes are alot more involved than you think.  Everything is on the wrong side. From the starter, wiring, can't  use the Chevy trans, fuel lines, radiator everything is backwards depending on your preference, Pontiac or Chevy. Once you get the swap completed the New normal is $2000 per second in upgrades/parts to get down to break 10 sec.  After that gets stupid expensive.

Excellent points.