im sure this is a dumb question....

my old boat im rebuilding is a mercrusier io. it has the old log manifolds and one is gone. I have a full set of aluminum hardine manifolds and risers. I could run the exhaust out the transom like a jet or vdrive. im looking for a full set of later mercruiser manifolds. but wanted to ask two questions. 1 how do you know the height of the exhaust going through transom and how do I figure out the height of a swim platform. ive never had it in the water. thanks for the imput......let her rip

 

Can you see a waterline in the boat's finish? A line of discoloration/dulling/scum line is usually visible unless it was trailer kept.

If not I would either look for the same boat and where its waterline is or put your boat in the water and mark it. I prefer the exhaust tips above the waterline and the back of the swim platform a few inches above the waterline so that it's not constantly slapping.

 

no cant tell on the hull. I tried its a 1980 marlin open bow 19ft. it has the outdrive hole will that help? I would love to make swim platform before its gel coated