A properly designed 3" system with X pipe shouldn't hurt your backpressure, plus you'll be ready if or when you want to do some upgrades to your 462.
I have a 3" system with X pipe on my basically stock HO 400 '67 GTO and have experienced no downside. I am currently using the HO manifolds with 2.5" downpipes tapered to the 3" headpipes. This system was installed in anticipation of a moderately built 462 going in at a later date.
All tests I have seen have shown the X-pipe making more power than the H-pipe and it does quieten it down some. As stated above though, it will be more difficult to fit on a system already in place.
|