Originally Posted by
MOBILEMERCMAN
I idle my 509's about 1000. works out to be about 750 / 800 in gear. Being a particular old fart I have me routines. Adjusted mine to idle relatively low. My reasons to keep on low side are to be easy on trannies and around the dock. Your trannies are pretty tough design but, reverse is the weak part. I try not to use throttle in reverse. As soon as I clear the dock I bring the idle in gear up to 900 or 1000. I try to never let it idle below that. It will but, I just don't let it.
After you go through the measure process hopefully you find there is a stock shelf part that works and you can save time and some money. It will hurt nothing to have regular hard wall wire exhaust hose to connect a bravo length pipe to your thru hull tips. Provided the tail pieces are pointing the right direction. The rubber hose will allow a little mis alignment.