Oh man we have the same headers! Ok here's the low down.
To install header studs on the drivers side, you need to raise the engine on that side with the header removed. Then install the studs (use a stud installer, don't "double nut" them) Then you will have to slighly dimple the tubes because the nuts are 9/16's instaed of the 7/16's they used to be. Work slow so you don't over dimple the tubes. The order on putting the nuts on is as follows:
Starting from the front of the engine on the drivers side, number each stud starting with #1. so the # 2 cyl. stud should be 1, the other side should be 2, the # 4 cyl should be 3 ect....
slide header onto studs ( with engine still rasised)and bring flange to edge of studs. Start nut 4 first, then # 2 and 6. then thread on 5, and 1 in that order. push header onto head by threading #4 until bottomed, then 2,6,5,&1. #3 should be no problem. The pass side doesn't require the lifting of the engine, and i have Vintage Air, si there is no heater box either. I love them. They got rid of all my exhaust leaks. Plus i also have that angled wrench as mentioned earlier, but Harbor Freight sells them cheaper.
1968 RS/SS Camaro w/ 94 vette LT-1 and T56 six speed, Cal-Tracs, Baer 12" crossdrilled brakes 17" rims, ect....
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My 68 with LT1 and T56</A>