I have one on my 6 pack Challenger. It has the modifications that were required by the old Direct Connection Engine book. I have the 3) 2-bbl Holleys that were a scat pack option. They all have accelerator pumps and progressive linkage. I have the 590 lift solid DC cam in the motor. Compression is 12:1. The transmission is the 833. The set up would work with an automatic but it had to have a high stall converter. When I restore my car, I plan to leave it on it. A newer manifold would probably be more efficient, but this looks better. It is taller than the regular 6 pack manifold. I had the shaker hood on the car and the shaker scoop, when mounted, was too high to close the hood. It will fit under the magnum and the T/A hood. The only tops I saw break were due to backfires when an engine let loose.