Regarding the collectors, if you have them off the car still, face them together where the primary tubes slip in. If you have two of the same side, one will be upside down (very obvious). The best way I've found to assemble the headers into the car is to: test fit each tube to the cylinder head (I test fit and label all the ones I sell on a spare cylinder head before installing or shipping, did you figure out which tube goes where ok?); test fit each tube into the collector at its intended location; apply antiseize compound to the outside ends of the primary tubes; starting with the center tubes, loosely install each primary tube; apply antiseize to the inside of the collector wher the primaries slide in; slip the collector onto each tube, one at a time; once they are all started, work in a circular direction pushing or tapping each tube in a little at a time. You do not want to get in a hurry and have a tube bind up as progress will come to a full and sudden stop. Call me at the shop on Friday if you're still having trouble and I can give you some more tips. By the way, where did you buy them and for how much?