I have a 2006 Silverado 34" radiator (on an '89 c1500 with a 4l60e) and I'm installing a B&M auxiliary oil cooler. I'm looking for the thread size of the cooler lines in the radiator.

I want to replace this


with a -6AN connector



Does anyone know what thread size the radiator has? The transmissions is 1/4 NPS, not tapered.