Hey tsnunamimike, have you tried sitting on one yet? That should tell you if your height is not gonna work. Have a chat with your local dealer. I wish I could give you a better answer. 320 is a good amount of mussle
to be carrying on a 250 but i have a hunch it will pull you. Just not to fast.
If you are not gonna ride it very far or fast it might be fine. If you hit a road irregularity at speed while turning might be bad if your maxing out the suspension. More of a safety thing. Are you staying off highways?