1998 225 Promax Drive Shaft length Question

[Beak Boater]

225 Promax, has a coned Torque Master 1.87 gear RH 20 inch mid. Everything works fine. Had a chance to buy a 20 inch 1.87 gear rh Sportmaster, Bought from a private owner. Tried to put it on and drive shaft is too long. Drive shaft on the Sport Master is 23 3/8 from the top of the gear case. Not water pump, to the top of the splines. I measured the drive shaft on the Torque master it was 17 inches, or their abouts I didn't get that critical with the measuring since it was obvious that the Sport Master drive shaft was different.
What do I have? is this for a 25 inch mid? Did different year sportmasters use different length drive shafts even though the mid is 20 inches? Not sure what year the Sportmaster is, its got the wide clean outs. On the parts look up, it lists X long, long and short for the drive shaft length no measurements. I need a sportmaster education I guess. Lastly what can I do to fix it. Thanks for helping.

[Merc 2.5]

Well for the fix (once u know what length) chris carson can cut and respline it, do u have a (known) 20in lower u can measure? Did sport master ever come with 25in shaft?

R u sure ur mid isnt cut down few inches? When tryin install sporty is it 5 in to long?
Do u have it mating with crank just rite?
Measure torque master and sporty side by side

[Beak Boater]

After talking to a couple of people....I think what someone did was used a 15 inch shaft and a 5 inch adapter. Don't know for sure until I pull the lower back off and check it out. The coned gearcase drive shaft is about 5 inches shorter than the drive shaft in sportmaster case. The measurements for the drive shaft of the sportmaster will fit. I just got to find out whats been used as an extension and how to get it off.