I have installed 3 sets over the last 6 months, 99 Ta, 00 SS, 02SS, On the 02 SS,first install, I cut about 1/8th inch of the block tab.Other than that small modification all three sets went in with NO componets having to be disconnected.(total time for all installs,including ory's was under 4 hrs) And looking back on it,after doing the other 2 sets grinding the tab wasn't probably neccesary. Now having said that the 02 SS headers(mine) were non emissions style,the other 2 were equiped with air/egr provisions. In this area there were some issues. On the 00 SS we hooked up the air but left off the egr because he was going with the LS6 intake and on the 99TA we spent about an hour trying to get the egr tube to line up before the owner said F*** it and was going with edit anyway and decided to delete egr also. Overall I would highly recomend these headers to anyone wanting a awesome hp bang for the buck