I got dumps w/ switches on my 69 428 mach1. You have to hear it to believe it. I've never heard a harley as loud as it. Mccord powerplates, are switches for dumps which run around $100 each, and the dumps were $45 each. for around $300 bucks you can have the loudest, meanest, raciest car in town.
It does tend to make it sound like a truck somewhat, due to no mufflers, but I have a cam, so it sounds like a nascar gone bad. there's nothing like having a riced out import pull up at a stoplight, then open the dumps all the way, and scare the wits out of him, ..........while your pulling far far away of course. No one messes with me around town anymore. I only run mid 13's since its stock, but they dont knows that
.......make the guys with hogs jealous! GET THEM!
just make sure u have headers, because if you let off the gas real quick with them open wide, some cold air be sucked back into the manifolds, hitting the hot valves, causing them to warp. With headers this is not a major concern, as there is alot of air resistance/confusion in the collector.
If you want any sound clips, pictures, or questions just ask