Headers?

Doug’s D453’s or TTI’s for best fitting. Either one may still need a few small dimples. Some cars need them, some don’t, that’s just life with the body tolerances on these cars. I have Doug’s on my Duster with a 340 and a 4 speed. I needed a few dimples for my 1.12” torsion bars but if I had stock bars they probably would have been fine. I also have the spool type engine mounts, so, no shimming like you can do with the biscuit style mounts.

Other than the Doug’s, TTI long tubes and TTI shorties, all the other headers will capture the steering linkage. The ground clearance isn’t great with those styles, they usually end up flat.

The TTI’s and the Doug’s both need a TTI z-bar, or the stock Z-bar modified to the TTI specs. TTI has a diagram on their website, you basically just move the arm on the transmission side to the edge of the bar and turn in around so the stud faces the other direction.

Either way though with pretty much any A-body header there’s no guarantee that you won’t need to dent, dimple or modify something. The stock 340 manifolds do pretty decent for stock or close to stock engines.