I had bought the infamous "needle bearing" type from 440 Source thinking it was a good purchase. I heard about meltdown due to those needle bearings and didn't want to be a statistic. I sold them and got my money back, put the money towards Harlands. I bought them from Todd at CompWedge (a member here on this board) I told him my setup (apparently the Eddy heads require some extra machine work which he provided) They bolted right on, no shimming, no guess work. FWIW, you do have to take them apart, just take a picture and put it back that same way. You have to let them soak in oil for a day or so then bolt on to the heads. I am honestly very happy with them but I only have about 1000 miles on the motor since the install....