I had an older 26 stinger with 350/375hp. I added the stainless marine exhaust, took the bottom paint off. I gained 6mph. On a GPS.

Not sure what got me the 6mph but I think a combo of both. I heard taking the bottom paint off adds 2-3 mph.. I think the exhaust definately lightened the load. ( From Merc cast to Stainless marine alluminum) I truly think I gained a few MPH with the exhaust too..

True, but you also need to add a lil disclaimer here about the increased dangers that come along with their removal.

sounds like a prop for this season and the rest will be the bling. i already wax the hull but it seems my boat runs the same no matter what. ive put it in the water, fresh waxed hull, clean as can be and smooth. 1/4 tank of fuel, nothing on the boat just driver and some basic stuff, cool air and perfect water. the boat runs 60mph on gps.

i have then taken it out, heat of the summer 3/4 gas, 2 people, a cooler with beer and 2 weeks of salt water growth on the bottom and the boat goes 59-60 on gps.

i then had 7 people, 90 beers, 3 coolers, food coming out my ears, cloths, an inflatable boat in the v-birth fully loaded, full fuel dirty bottom etc etc etc and the boat still did 58 every time and 59 running with the wind on the way home with a little less fuel and a tad cooler air. its strange, but the boat runs the same pretty much all the time. lol seems fully loaded i can trim it up more tho befor the prop starts to spin so maybe that is the key, getting the boat up more with a little more prop.
i'll find out, im going to be calling todd this week to place my order.

A new E-Top for the 496/GM Big Block
Released at the recent LA and Miami shows, replaces the stock height riser exhaust and fits to original tail system or silent choice Y pipe diverter. CMI system at competitive to cast aluminum pricing. Fits 34.5 centers.Attachment 378050