You can cut the column tube back to help some with that but that means you're going to be taking the column out and apart.
Is it too late to back out and go back to manifolds? LOL.
That reminds me at one time I had a 67 Dart GT 273 with headers on it, and it seems like they were big tubes. I need to search those photos out to see what was done there.
I got mine used, from a member on the site for a good deal. My first thought when they were hitting after I dropped, the jack was your thread, and then I wonder if someone would want to trade for some 340 manifold?!?!? lol