I have a 26 a/o with the prop shaft even with the center pod , and I am getteing a lot of slip at mid rage. As soon as the boat rolls over the prop ventilates, Above 80 it seems to grab better. I am going to try a 5 blade next. 489 procharged chevy 32 pitch 4 blade I'm running 94 gps @ 5500 rpms. I'm only running about 44 @ 3500.
Wuped your prop slip must be pretty bad because at 4000rpm im running 65mph at 4500rpm im running 87mph. And at 5000 rpm im runnning 94mph. Thats with a 1.34 gear. You might want to think about a one inch spacer.