I have always heard the older coolers had 6 o-rings but only for the first couple years or so, after that everything is 4 ring. 8v, I don't see how you got yours back together the way you did, I used the bottom of a tractor and a 12 ton bottle jack to reassemble mine and I had to do it very easily. I used a very fine emory cloth to clean up the surface s inside of the headers where the o-rings went and then covered them in vaseline, I also covered the orings in vaseline, and then pushed it together with the jack against the bottom of the tractor. I could tell it was even beginning to take some weight off the tires before it finally seated the o-rings into the headers. I went very easily though because I didn't want all the weight to slam it together when it finally did seat.