I have started cutting the rot out of this 17' tri-hull and would like to run stringers for a 4.3 instead of the mercruiser 140 i pulled out. I took the transom apart today and am thinking i should have sat a 4.3 in first to see where the new stringers will need to be. Have i messed up or is there some where i can find the measurement for stringers for a 4.3?