engine swap transom height/wiring

My old Johnson 115 finally died, as confirmed by a 0 PSI compression reading on the #1 cyl. I bought a very healthy 1990 Johnson 90 HP as a replacement, but I didn't notice until I purchased (way too hastily) that this is the 20" model and not the 25". My current 25" outboard sits with the anti-ventilation plate right at the keel height. Given a 5 inch decrease in length, the 90 will sit about 5" higher. Am I screwed? The only alternative I see is to swap the powerhead from the 90 to the 115.

Also, the wiring harness on the 90 is different from the newer 115. The 90 has the old 8 prong red plug connecter, but my wiring harness right now is all deutch connecters. should I simply cut off the connectors and butt splice each wire? Or maybe male-female plug each wire? This would work, correct? Thanks.

Re: engine swap transom height/wiring

Go talk to a BRP dlr. They make adapters for the wiring harness for the prob you have.

Re: engine swap transom height/wiring

Could I technically just butt splice each wire?

Re: engine swap transom height/wiring

Yes you can, if you use the right connectors and seal them real good. Butt ( pun intended ) if you want to take the mtr off you'll have to cut them.

Re: engine swap transom height/wiring

Sounds good, looks like johnson used the same color codes for both models. As far as the height,
Im planning on running with the 90 hp 20 inch shaft this weekend, and if cavitation becomes a problem,
Ill have to start looking into mounting the 90 powerhead on the 115's 25 inch mount. Not sure if theyll mount up tho. The 115 is a 1997 model and the 90 is a 1990 model.