The M/T, Holley, Wieand, and Cal Customs that I owned in my life all worked with factory exhaust manifolds.

I have not yet tried the Mopar brand ones. I own a set.

Too many cars, too many parts, too little coin, too little space to work in, too little time left to make it all happen! Update: down to one ride, still too many parts, a little more jingle in the pocket, gaining space, and it's going to happen this year!