Welcome to iboats
Conversion is more involved then removing the I/O, bolting on a pod/bracket and mounting an OB. Esp if you intend to cut the transom down and mount the OB w/out the pod or bracket.
IMO, a well done pod/bracket install on an 18.5ft aluminum boat will support a 140-150hp OB.
Why convert it from I/O if it's setup for that now.
Got pix?
Pix help
http://forums.iboats.com/forum/forum...pload-tutorial
And the HIN, which should be on the title/reg [but those also list the year], will tell you what year it is.
www.HinDecoder.com
I suspect Rapala was the preferred brand of fishing lure of a previous owner, not the boat model. The seller couldn't tell you year and model?
What type of boat is it: Cuddy/Cabin/Open fishing/Center/Side console?