Similar problem as machzer. 98 mach 1, stock pins, 286, #3, 230-390 sping, 50 helix set at 19lbs. It dies off at around 85, and pulls ever so slowly to 90. I keep blowing belts, checked alignment, a little off. Reset alignment w/ sno stuff tool, could not get back contact point to touch no matter what I did. Center/center ok. I was thinking of 53-44 set at 16lbs? i have a fairly good set-up w/sc-10 II, mxz front springs, 192 studs, precision skis, and sway bar removed. Front end feels so much lighter, and it dosent push any more than before, so if I could get that power down I would have a fairly decent all around sled, any ideas?