are you sure the OD of your log exhuast is a true 4"? i thought it was like 3 1/2"?
if its 3 1/2" you'd have to make up the difference with some tubing inside of tubing which is kinda hokey... not sure id want it coming loose and having a 4" hole in the back of my boat all for the what... 2hp its going to add if any?
its a bummer that sites like cpperformance run sales on 4" stainless tips for almost 2 years now, yet the 3 1/2" ones are full price at like $125. i hit them up a long time ago and they basically said "go away jet boater!"