There are minor differences in frame dimensions and offsets between the two. As an example...RT rear fender struts have a different offset than the DT struts; so sissy bar kits are not interchangeable between the different frames.
Ones a foreighn bike the other is American .
Only kidding !
I also beleive the compensator sprocket offset is different also > Transmission to
motor offset .1 1/2 " Daytec . 1 9/16 " Rolling Thunder.