How are they plumbed there (at the trans) EDIT dont tell me that each cooler fitting at the trans has a T and the fluid is going out to the coolers in parallel instead of series . MORE EDIT The orifice in the trans case would be the same dia including the ID from there to (& including) the T fitting so there would be no increased flow. Best would be to plumb em in series or if starting from scratch to drill out the case for a larger ID fitting & use the next size larger (3/8 I think) tranny lines and an aftermarket cooler w larger fittings for 3/8 lines & not use the oe bottom tank cooler at all expecially as I like to keep the ATF far away from the coolant and myself I dont think the trany fluid needs to be warmed up from the coolant. All a moot point w a /6 just thinking out loud