on a imco sc lower how can you tell the ratio with out tearing apart and counting the teeth, only thing stamped on the case is -2 any help would great

As far as I know, there is no way of telling with out tearing it down. The -2 means the case is a 2" shorter case.

on imco website the only option they show for gears in the sc lower is a 1.50:1 so that should be what you have

You can order the SC with various gear ratios and they are determined in the lower..

15/19, 1:5 = 1.26666 turns of the Vertical shaft for each turn of the propshaft

15/17, 1:346 = 1.133333 turns of the Vertical shaft for each turn of the propshaft

17/18, 1:25 = 1.0588235 turns of the Vertical shaft for each turn of the propshaft

You can turn the vertical shaft 10 times and multiply the results by 10 and see a more accurate result.

But that should tell you what lower gears you have, then you have to combine them with the upper set to see overall gear ratio.
If you have B1 upper gears 27/32 or XR 16/19.. the ratios I gave you for the lower combinations is true. If you have B1 upper ratio, then it changes the over all ratio.
B1's used to determine over all gear ratio in the upper..

So do the turns thing and tell me what you have for an upper.. We can find what ratio you have.

Dick

the upper is a 1:36 but the gears broke in the market for a new stronger upper, was thinking of going with 1:50

I did the turns the shaft turned about 1.25 so it looks like it is a 1:50 gear thanks for the info