Put in the Barnett Carbons and springs also. Fixed the slipping but, does make a harder shift and neutral find. Some folks use the dimpled stock plates. Says it traps oil and reduces heat. Something to consider. Didn't shim the springs (didn't come with any) but, doesn't need any more tension anyway. Hooks up just fine under heavy load. Did use a touch of Blue Loctite on the bolts, just to be sure they don't back out.
My experience has been about the same as the above mentioned. I started getting slipping really bad about 15,000 miles in. I choose to ignore it for awhile. Eventually this board convinced me that springs would do the trick. Bought them and installed. Less than 1000 miles and it was slipping again. I ignored it for another year before once again listening to the board. I bought and installed the barnett system. NICE. I never really realized just how bad the stock plates were slipping. I've got power back in places that I didn't realize was lacking. The down side is while the clutch was bad, I got the best tire wear ever. I made it one whole year on one set. When the clutch works I usually do two sets per year. At any rate, I love the Barnetts even though shifting is a little different now and neutral is hard to find. Do it again ? Hell yeah. Should have done it the first time instead of wasting money on those stupid springs.