I am wondering if the ratio can be changed easily on these units? I am looking for a 1.56 ratio, but have found other ratios for sale. Also I am just wanting to know as much about these units as possible. It seems odd that all the trans from BAM are 1:1... Does anyone know of other options to modify final ratios? I can get a pair of 1.3 but would want the final to be 1.5-1.6. What determines what the best ratio would be for a given application?

Bam transmissions are utilize a 1:1 as it makes for the strongest/ smallest package with the Borg Warner 72c transmissions. You could always locate ZF or twin disk transmission that have different ratios available and some models are 2 speeds. They are inherently larger and heavier -- but do offer the ability for a reverse rotation at the same hi torque numbers as forward rotation, a nice option if your Arneson drives are both same rotation... The boat, weight, hp, all determine the "best ratio"
Good Luck

Arneson drives have a chain drive or gear drive for the counter rotating prop.

Gears and sprockets for the chain can be sourced from Rik at Arneson Industries.

So I am doing a Bravo conversion kit so Rik is telling me there aren't any good transmission options. He can change them to the 1.56 but it will cost over 5k to do. I was hoping someone out there has done this themselves... All the signs were pointing toward these being easily servicable...

What was the quote for the gear set and sprocket/chain set?

Or did he only quote the complete service cost for in-house?

are you tryig to work around him? hes the the guy so what he says is most likly true