Tamaha T-50 vs F-50. Differences?

[Vance in AK]

I've picked up an 87 20' Koffler Lite sled with a 2004 T-50. I'm wondering what the differences & advantages/disadvantages are between the T & the F?
What areas of the engines have parts interchangeability?
It's a fishing boat for the Kenai etc right now, but hoping to do Yukon or Tanana for moose with it in '15 or '16

[Akfish1]

The difference in the two is entirely in the lower unit and prop. The T50 uses a 6E5 type prop similar to a 90 or 115 and a 2.33:1 gear ratio versus the 1.86:1 gear ratio of the F50. With a 20' boat, the T model is the way to go. As for interchanging parts, everything from the midsection up is the same between the T and F models.

[iofthetaiga]

Doesn't the T model have a different engine configuration too?

[Vance in AK]

Thanks Akfish1.
Is there a site that really explains to the dense how the whole prop & gear ratio thing works? I mean I understand gear ratios in cars & trucks. It make since that since the T is geared lower it would come out of the hole better (Drag racer with 4.11 gear ration vs family car with 3.39 ratio). But then you put a prop with more pitch & greater diameter that takes more power to swing so it seems that would defeat the lower gearing (that gets a heavier boat on step faster). Is it because the prop "slips" until the boat develops speed?
It would almost seem that the F50 with an 11&3/8 x 11 prop would have the same approx final drive ratio as the T50 with a 13&5/8 x 13.
By the way, have a prop recommendation for the T50 with a 20' Koffler Lite sled?

[Sobie2]

Go look at the props the F50 normally runs, and then look at the props the F90-F115 run. You will see a huge difference. The F50 runs a 3.5" gear case turning mostly 10" diameter props. The T50 runs the 4.25" gear case turning the 13" diameter props.

Sobie2