Dizzy, off topic, but man that rear fender is awesome!!
The peanut tank will do it just right .... great taste my friend!

 

I was interested in doing that too. I think a fuely sporty tank would connect up to the motor fine and the front mounts look similar. The sporty tank may be shorter...not sure, but I think it could be fitted with some fabrication. Big problem I think may be that the newer Dynas have a thick square frame tube and the sporty tank may not fit over it. I finaly ended up just getting a used sporty and kept the Dyna too. That little bike is really alot of fun, and pretty dam quick too. Not as civilized as the dyna, deep gutsy growly sound and feel to it, great city bike.