After the cowl had cured I installed the thru transom exhaust extension before the decking goes on. This is nothing more than a piece of left over 7/8" aluminum tubing from cutting a header pipe for the motor. The hole in the transom is drilled slightly down & towards the center while the part on the outside of the transom is cut flush. 2 layers of 1oz. cloth are wrapped around the tube to 'glass it in place.
