Since you're running the 212 which has more than double the hp mine did, I think you can safely run 8:1 or even taller. 7.5:1 will give you just over 1mph per 100rpm.. so you can use your tach as a speedometer.
You can change it up but that clutch will chatter and heat up if you dont peddle off the line to build up some speed. I could not deal with the max torque issues and went to the disk type.
greaser_monkey_87 made a thread about tuning the MT. TLDR: alternating heavy/regular shoes with a black spring.
http://motorbicycling.com/showthread.php?t=55901
On my auto shifter the first gear was also low at 12:1 but it only chattered up to 15mph and it didn't bother me much.
I made an XL chart where I calculated maxTorque spring and weight effects based on my own experience, for the 2nd gear shift,
in which we only care about full lockup and not start of engagement.
Note that the numbers may be a little high, but when I changed springs between the silver and yellow springs and put the corresponding shoes, the numbers were dead on within +/- 100rpm. Remember
initial engagement can be as low as 600rpm under full lockup
I ran a top gear of 7.64:1 and I only had 3.5hp (ratio on the left, yellow spring mixed shoes)