Juan,
Corner weigh if possible. If not, max axle weight/2 will get you started. Set the tire pressure to minimum for the weight, using the Michelin chart, plus 5 psi. Start adding 5 psi to the front axle and see what this does. If no improvement or it worsens handling return to original psi and do the same with the rears. Keep moving the pressure around until you find your best handling with out upsetting the ride quality. It took me 2 pressure adjustments to dial in my HR. You could get as lucky or you could spend all day. Once you have done this then you can really consider throwing money at suspension mods. Also a light hand is a necessity because of the rear overhang. A slight change in your driving style can make a lot of difference.
Randy
