I myself have never heard of this BUT if the cooler
doesnt flow for crap then the back pressure backs up
but I didnt think that would be in the conv... I basically
buy coolers that have equal or larger lines than the
5/16" of the trans... my 518 trans has 3/8 lines from
the factory and the cooler has 1" tubes but necks down
to just under 1/2" so the 3/8" hose(short pieces)
just works on.... plus I enlarge the trans fittings
some by drilling the ID out a bit... just for a bit
more flow