Has anyone ever replaced the stock exhaust on a 496 Mag or HO? If so, were there any hp/torque gains?

Several boaters have added CMI E-top exhausts to 496 packages. Our dyno says its worth about 20HP at the Crank.
Raylar

Thanks for the info!

Will the standard big block CMI's bolt up to the 496 heads or does CMI make a different header for the 496 head?

Don't waste your money. The exhaust you have is designed for that motor. You will see no performance gains,

I agree with Pure Energy. My $00.02 says that even if you get 20 HP at the crank, the expense is not worth gain unless your old manifolds are/or are about to start leaking. Save the bucks now and make them grow until you can (Upgrade engine, install S/C, Cam, heads, intake and carb/injection improvements.) How many of us installed headers on our old cars and without doing anything else to the engine saw an improvement, other than the "coolness factor, as... I got headers an' you don't". don't get me wrong, on the right engine Hi-Perf exhaust is a MUST.

I'll probably stick with the stock exhaust for a while.