I have a 1985 Mercruiser 3.0 4 cylinder in a 19 foot Wellcraft. As I understand it this engine is based of the early 60's Chevrolet that was offered in the Chevy II. I have gathered up the parts that I think will be necessary for the swap. I have the TBI unit off a 3.1 Lumina van, the wiring harness was pirated from a mid 80's S-10 with a 2.5 and a manual tras. The ECM is a 1227747. I've fabricated the adapter to replace the Rochester carb with the TBI. I have the Howell manifold adapter to put an O2 sensor in the "wet" exhaust manifold riser. I bought a Moates tuner, cables and such. So I'm now ready to install it and need some help with or ideas about the "tune". As I understand it, I need to change some things in the ECM or prom, In no particular order. Slow the idle down to allow easier shifting from neutral to forward or reverse. Hook up the shift interrupt switch to "kill" the spark and therefore the torque to the outdrive. (again to make it shift from forward or reverse to neutral). Also need to change the temperature that the ECM goes into "closed" loop as a boat getting fresh water for cooling will probably never see over 180 degrees. (It does have a 165 thermostat). The mechanical aspects of this project I can pretty easily handle, but the computer programming seems a bit overwhelming. I tried to search in another site that deals with boats only and was chastised for putting a "non" marine set-up on a boat. Now here is how I see it, the biggest concern is the explosions that have occurred in boats in the past. I feel the TBI will actually be safer as gas fumes will surely be less with out a vented to the atmosphere float bowl. Any and all constructive ideas will be greatly appreciated.