the same one, the one that runs to the evaporator. but most just use the KA compressor and swap out the line. the r134 one, the hose that gets swapped, port and the hose it's self is smaller.

i would rather run the r134 compressor cuz 1 the r12 compressor does not fit at all with the newer black top r134 compressor mounts. i think i can get 1 of the bottom bolts to line up, or both the tops if i grind off the lower support tabs. but i would rather not do that.

2 r134 is just a hell of a lot cheaper and i would think other than this hose issue, would be cheaper in the long run.

i was hopeing maybe there was a reducer adapter that fit from the S13 r12 stock line to the size that would be used for the r134. something like this, the male side larger than the female side and reduced the over thinkness of the line. i just need to fine the right size of the in and out. http://www.hoseandfittings.com/catal...6765.6821.6258