here is a pic of the AN fittings for trans cooling lines-they screw into a 4l80e, should fit 4l60e, and i have used them for 400's
im going to try and bore one out to press in the 3/4" of 3/8" line for the
4l80e rear line-
their 1/4-18 straight pipe, not tapered, from ATI Perf Transmissions