Wayne,

The Nova Rossi 13 that I'm Running has a pipe length of 14 1/2 to the High point of the pipe I'm running the stock Nova Rossi Pipe.
The motor turns 14,100 on the test bench with a 11X10 APC prop. Don't know what it turning in the air but I'm more than pleased with the prop and the performance.
As far as the plugs we can send you as many as you want and have them to you before you leave for Hodges. The plug Rossi recommends is the C6S.

Dave.