1992 Mariner 115

[sprintracer6]

I just purchased a used 1992 115 hp Mariner Outboard that has a 25 inch shaft, & I am planning on installing this on a 24' tri-toon, people are telling me that the 25" shaft motor will not work on my transom. Any validity to this? Also, the person I purchased it from tells me that the 5" shaft extension can be removed & the lower unit put back on to make it a 20" shaft motor.

Any feedback from all you pros would be appreciated.

Thanks in advance
Doug