vs 1400 final drive in a vs 800

hi all, firstly hello this is my first post and secondly my apologies if i am posting in the wrong place as this is my first foray into forum chat.
my situation is i have a custom i have built using a xv750 engine and vs800 wheels front end and drive the rest was made from scratch ( the wife has a vs800 intruder trike). now its on the road i realize the engine and final drive are not really compatible, it basically revs to high.
my questions are dose anyone know the ratios for the final drives of the vs 600 vs 800 and vs 1400? not the info you can get from Suzuki as that will take into account the rotation of at least one cog before you get to the drive shaft, what i am after is purely rotation of the drive shaft to one rotation of the back wheel?
also i see a lot of people are doing the 1400 to 800 diff swap but it is not vs to vs, i have not seen any info to suggest the compatibility of a vs 800 with a vs 1400 diff.
also is the vs 600 and vs 800 diff a strait swap no mods needed, if so dose the vs600 diff have a different ratio to that on the 800?

 to clarify something from above if you ask Suzuki what the final drive ratio is for the vs 800 and vs 1400  they will tell you its 3.09 :1 and 2.66:1 respectively ( i think, i haven't got that info at hand at the moment) but i know from the bench test that the vs800 is a shade over 4:1 when only involving the shaft to wheel ratio.

i believe that the vs 1400 diff would be a better match to my engine but i dont know if it will fit in the frame or the bolt pattern line up( it mounts to the original vs800 swing arm.) i am ok for a bit of machining if necessary but i don't want to buy another diff if i haven't got any chance of making it work.

thanks in advance and i eagerly await your knowledge.

I have grafted a final drive(driveshaft and diffhead) from a 1400 into a c 50 (800 cruiser) the only things I had to do were shorten driveshaft approx 30mm(disc grinder and steady hand) and slightly oval the three mounting holes in the c 50 swingarm-driveshaft tunnel. it has transformed the bike from something slightly breathless at 100k into a very relaxed ride. I highly recommend it.