First modification almost complete on my project. I've wanted to add the pivot to the T-20 for a long time. Finally figured out an easy way to do it with my basic tools.
Drilled center pivot hole in U channel. Same size bit used to tap a 3/8 hole.
Installed U channel on transmission using just the bolts to keep it from moving. I made sure the hole was centered on the casting.
Using the U channel as a guide, I drilled the hole into the transmission.
I will enlarge the hole to 1/2 for a bushing. I will be using 3/8 ID - 1/2 OD spacers or bushings for the U channel pivots.
I also enlarged the hole for the hairpins to one size over 1/4 to use 1/4 inch pins to take up the slop between the bolts and the pins. (drilling it 1/4 didn't give enough clearance for the bolt) I will also slot the heads to make adjustments easier.