i wrapped the chain around the largest front sprocket and the largest rear sprocket (with the derailer swung out of the way) and marked the chain at the first possible link to get the chain to fit around the sprokets. what i'm wondering is if thats too tight for the derailer to work properly...
if you have worn teeth on the ring gear you'll have to separate the engine from the tranny to replace the ring gear, can be quite a big job since you'll probly have to pull either the engine or tranny whichever is easiest to pull.