Transmission swap ?

I think that by the time you figure this all out,your rebuilt one would be back IMO.The PCM trans has an angled output shaft so the engine sits more level,I also believe it changes the rotation of the prop so the engine is a left rotation and the prop turns right. Others who know the newer boats will be able help in the morning.

the 1.23:1 has an angled output so the engine sits MORE level. they did this in late 80's as a PowerPlus package because it allowed the front cylinders to receive more fuel and the back cylinders less so its more balanced as they found when the engine is inline with the prop shaft the front tended to run lean while the back ran rich. The PCM 1:1 is an inline transmission. This will be a huge challenge if its even remotely possible as you would need engine mounts with big adjustment and you need to get every thing lined up perfectly or else it will fain in short time.

So it would be best to buy a new 1.23:1 or have it rebuilt.

I guess I don't understand didn't some of the ski nautique come with a 1/1 transmission . did they have different motor mounts . or is it just a matter of realigning the engine .

it depends on the year. the 1:1 transmission requires the engine and transmission to be in line with the prop shaft. when pcm made the 1.23:1 transmission they angled the output so the engine could sit almost level for a more efficient engine. they called this the "PowerPlus Package". many boats went straight to the PowerPlus package for more performance at not too much more cost.