alot of people don't like blocks . .because they can kick out . .in fact adam (crxextreme) kicked his out the other day . . but had degree shim and block stacked and it broke the center pin on the degree shim . .. don't know if his u bolts worked loose or what . . i never kicked the blocks out form under my truck. . . i wrapped and bent my rear leafs but i'm running a 500+ hp big block and was running 44's . . with a 4 inch block in the rear