55.2-59 700r4 cooler lines?

[regan56]

folks..

i have been making modest progress on the '56 GMC, not breaking any records, just nice and slow as the $$$ allows.

I'm to the point where i have a rolling chassis, trans and motor set (still some work to do to get my angles right, but thats another thread).

my issue right now is the transmission cooler lines from my 700r4. through some research I've found that my trans is a '90 model MD-8 case (0CH[R?]M166B). originally i had in my mind that this was from a '91, but its not.

anyway i went about ordering fittings from my parts guy who looks up my trans (no a big chain, local shop, never let me down type thing) to make my own cooler lines (aux cooler to be mounted in front of my stock rebuilt rad). get the fittings, and they are too large?! ok, i return those and go teh stock OE replacement route and order OE replacement lines for a '91 2wd Chevy 1/2 ton 700r4. Again still thinking i had a '91 trans. Dorman parts 625-161 and 625-162. They come in the courier and alas, too big again?

its at this point I begin to doubt myself and my memory and set to research where to find the ID number for my trans, and find the number above, identifying as a '90 model, 700r4 (has the rainbow / casting defect at the connections do things are lining up so that's good.)

Surely things didn't change btwn '90 and '91 in terms of the fitting size on these trans? the same part number from Dorman says it will work on a '90 model? have i come across a 'white buffalo'? or am just not as astute in finding parts online as i thought?