" Kirk I am not an expert on t
" Kirk I am not an expert on the subject nor any other subject for that matter, but I have done this very thing on a mid 80's Johnson. The conversion I did was just the length change, not the console to tiller for the steering. The most expensive part was the driveshaft. I don't remember the cost, but at the time I thought it was an awful lot for a simple looking drive shaft. I didn't re-use the parts associated with the water pump. Since I managed to do it without much trouble I would say the length change is an easy job that cost at least $275.00 1983 dollars.
Best regards and good luck with it,
Frank "