38ZR 700SCI Prop Question
 

I have a 38 ZR with 700SCI and NXT drives. I am thinking of trying out some different props I am not sure what gear ratio I have in the drives. The boat cam with 5 blade Mercury cleavers 17.00 37 15R props.
Just wonder what other guys are running that works with this set up. Is there a way I can find out what my gear ratio is in these drives?

Thanks

those props are something like 15 grand a pair. Not many people tinker too much with props when they are in that price range

There is usually a tag under the tiebar plate on top with the overall ratio or there may be a stainless head screw underneath the horizontal edge on one side of the upper housing toward the transom bellhousing with a stamped in ratio. The screw is difficult to read upside down, but maybe with a smartphone camera you can get a snapshot of it. I have seen both wrong because ratios were changed after factory build and not remarked.
If you want to do a physical check and have good enough access to the driveshaft, you can put a degree wheel on the propshaft with a pointer and rotate the driveshaft "exactly" one revolution and read the rotation angle at the propshaft to find the gear reduction. I have a chart with the angle calculations for the various ratios, but you can do the math to figure it out too. Example: Driveshaft 360 deg rotation / 240 deg propshaft rotation = 1.50 ratio
With a 37 pitch prop, known speed and rpm, an estimate of slip (over 10% on a performance v-bottom), a prop calculator could point you to what ratio you have. My quick guess, depending on exact numbers, 1.5 ratio.