Center to center of pulley 29 1/2 .. Bottom 30 tooth .. 5 inch diameter.. Top 3 inch diameter 20 tooth.. Not to sure on top.... Motor is a 22hp predator... Roughly 3000rpm to 3300... With an 11x10 prop idle at 7mph .. Open at 14mph with load... With a 9x7 speed prop from hill marine... A 9x7 with extra pitch and cup.. 4 mph idle loaded.. To 10 mph loaded... I want to stay within 9 inch diameter rule we have... Will a 9x9 be about right???... Picture shows what the ass end it has...... I know sponsons are a no-no but it was necessary or it would sink... I didn't feel like tearing apart a smaller motor and missing at the moment