thoughts on cam?

I would run a MP .455 lift 268/276 duration cam. It is the 340 replacement cam. Idles as smooth as a 318 2bbl. I ran that in my J head 360 with 750 dp holley, 10 inch TCI converter with 3.23 gears and ran 13.30's all day. One guy got 12.90's with about the same combo I had but ran 3.91's, but he did NOT have headers, he ran 340 manifolds on his 360. Just another option, I guess......