I have a question for everyone that can wants to help by answering, I was thinking of getting header side pipes for a 1967 corvette as they by what research I have found are roughly the same width as a van. Yes I know a van is technically wider but I am referring to where they would mount along the side of the van, could be wrong but was curious to see if anyone has tried this and if it would work or would I need to modify them to work?
I think the STOCK side exhaust for 67 came off a rams horn manifold and then the pipe made a bend toward the rocker panel and then was basically a chambered pipe type muffler (like the GMMG muffler) that ran along the side with a cover. However, I know there are headers available that have the collector pushed all the way out to run parallel with the rockers and a side exhaust can bolt directly to those collectors. Are these headers what you are wanting to run? if so, a 3rd gen chevy van is about 10" wider than the vette so I would assume you would have to cut them and weld extensions into each pipe to move that collector outboard to match up with the van rocker. I would find a C2 vette and measure the width at the rockers and then measure the width of your van to get an idea of the difference. also, I know that people use 2nd Gen F body headers on vans a bit, but I don't think I have ever heard of Vette headers being used, so there may be some other clearance issues there, too.