Matt,

I'm not really sure what the prop is intended for. It says 18x10PN on the prop, but Anthony R saw it and told me it is an older discontinued design. Does indeed have a totally different profile and looks a heckuva lot more like a sport prop when compared to the more recent pattern props, which I got from Central Hobbies.

I don't recall exactly where I got the 18x10PN... maybe/probably from Tower, when I bought the header. My buddy Rob has a recent-vintage 18.1x10 pattern prop he has offered to lend me for testing, so I think we will give that one a try as soon as our schedules converge.

If that doesn't happen soon, it is likely I will try the 17x12W and the 18.1x12 pattern just for the heck of it. Up until now I haven't been interested too much in the tachometer because of the exhaust issues (the depressed rpm's were depressing me!), but now that those are behind me it is time to get some serious numbers.