I never said it was easy.
Well, the guy I recieved the info from may be completely rong or partially rong. It dosn't hurt to do the research.

Jackd,
Since you have these technical manuals on an assortment of Mercs, check and see if any other con rods will work or would be easier to adapt to the 350 crank. Inline 6 or inline 4, check it out!
Thanks!
Adam