Anyone Know I.D. Of Oil/tran Lines?

I'm about to order fittings from Dakota Digital that insert into the oil and transmission lines to hold temperature sending units. They are available in either 5/16" or 3/8" I.D.
Dakota Digital technical support thinks the 2002 5.3L Avalanche uses 5/16" for each, but say that they're not sure.
Can anyone confirm the I.D.'s?
Thanks in advance. ?

Jeff Friley at DeLillo Chevrolet had one of their tech's answer this question.

Oil lines I.D. = 1/2"
Trans lines I.D. = 10mm

Can anyone confirm or deny these dimensions?

T.I.A.