I've been told 8-12hp of the hp increases with performance exhaust is the result of the turbulators being removed.

Yep. See the "496 Mag Dyno Testing & Myth Busting" section in:http://www.fullthrottlemarine.com/

Hi, I have a donzi 35zr with 2 496 with Corsa Q & Q, do you have an exhaust kit for me that replace the original exhaust?
I need 2 kit so, could you make a special price?
Thanks

Here are before and after prop shaft dyno sheets for CMI sport tubes on a stock 496 HO.

Anybody have the dyno results for the E-top headers?

My 2 cents: 27 Fever, 66mph on Fountain performance report with stock engine and 24" prop.
When I bought her, the previous owner had her fitted with sport tubes and a labbed 26" prop.
Now good for 70mph, but I can't say how much is courtesy of the prop or the exhaust.
My guess is that neither - alone - could have given a 4mph improvement. So half and half, maybe?

anyone have before and after sound clips of CMI E-tops?

I would like to see a pic of the E-tops on the 496's if anyone knows where one is.