Like Saxjohn said, they have different mounting spots, but they can be made to fit if you're creative
back in 84 I bought a Bassani Header for my 80 LTD & had to figure out how to mount it, & had to make a bracket to make it work, ....I wasn't as creative back then, but this is what I came up with, and it worked perfect
The middle hole was bolted to the stock muffler hole, the top hole was where I put the foot peg, & the hole with the spare socket in it ,to keep the canister from hitting the swing arm ,was bolted to the stock foot peg hole
I was young & Dumb, but made it work