I`m doing a set right now.I replaced the rocker shafts with new "Eastern" rocker shafts. I set the lower rocker blocks on the dowels on the cyl.head,with the shaft laying on the lower block,and rocker pad on top of valve stem.Now I slide rocker shaft to right and left,to centre pad on top of valve stem.This way I know which end of rocker block to braze,to get rid of the excessive end play.(If you braze wrong end,the rocker pad may be hanging over edge of valve stem.) Then I braze the end of the block,and clamp it onto a 7/8" x10"long shaft,and chuck it in the lathe,and turn the brazed part down until I get about .005 or .006" end play. Then I take it to my local auto. machine shop,they face a few thou. off the two mating surfaces,then line hone on their Sunnen hone to fit the new shafts. I know,it seems like a lot of work,but it is a good fix,and it beats that cheap Taiwanese crap,that C.C.I is peddling.