I'm using 2" brass pipe nipples from a standing lamp for the trans cooler lines; using a jam nut & teflon tape. Works great, though I wonder what I'm supposed to be using. PO had a too-small aluminum radiator that cracked, and was using about 6 NPT-> Brake line -> ??? adapters which dripped like crazy. Eventually hope to add a dedicated trans cooler as well, can't be too careful w/ this crazy LA heat.