I have the same problem. I kept the drums out back when I did the five lug conversion, and my left front will lock up a little quick. I've practically begged Matt for advice, but he hasn't been very helpful. In my experience, if I you ask him an involved question, he just quotes his site (which I read a dozen times already) and gives short, non-specific, smart-assed answers. The last three emails I sent never got responses. On a more positive note, I did improve my braking situation by adjusting the backs a little tighter and loosening the adjustment screw on the booster a turn. It took some of the sponginess out. I can live with my brakes now, but I wish they were a little better. I think the ultimate solution is to use the '93 cobra M/C and do the 3-2 port conversion, gutting the stock proportioning valve and installing a manual front-rear valve. I still don't know if the stock '93 booster will work with the '93 cobra M/C. Maybe some of you guys can answer that.