Corvette Performance - Is there much power lost thru stock C5 mufflers?

I'm running 1.75" LT headers with 3" catless X pipe thru the stock C5 axleback on my H/C/I setup. The quite sound is nice while cruising. But do the stock C5 mufflers rob much power over something like the Z06 Ti system or other aftermarket systems? I've read there isn't a big difference between the Ti system and aftermarket, power wise. Are the C5 mufflers more restrictive then the Z06 Ti's? How do they compare.

The stock C5 mufflers are definitely more restrictive than the Z06's Ti mufflers or aftermarket. On a H/C/I setup I would guess anywhere from 10-20RWHP.

I don't know about 10-20RWHP... That seems like a lot. But they're definitely not going to flow like the Z's Ti exhaust. As far as I know, the Ti exhaust flows better than all the aftermarket setups other than the LG Big 3.