250r to a 350x machine

[fastleo]

i have a trx 86 250r frame that is set up to ride a 300ex motor, but it has no motor only a roling frame. i alsp have a 300ex 350x conversion and it runs but im looking to improve my ride. first of all is it possible???? and if so how should i mod it. i did some research today and found nothing. how should i do this to have the the power i have on my conversion with the ride style of a 250r?

All ideas greatly welcome... thanks andy :D