I had a few of the smaller pylon props. I can't remember the numbers but the biggest was an APC 8.75 x 9 or similar. I had the narrow, normal, and wide versions. The bench RPMs were no more than that of a standard APC 10x6. The Viper had too much drag for the narrow style props so I put the 10x6 on and that's what sung the best. I need to order some other props around that size and play a little. I'll also look at the exhaust......don't want black. I'll also lower the compression and see what happens.

I was hesitant to tell what I actually did with the pipe as many will tell me I'm crazy. But yes! There is almost enough straight section on the header for the coupler to be comfortable and the pipe is just taper! You should have seen the reactions as I made 1" cuts to the MACs pre-tuned length. There are a few more believers now. LOL!