Wes wrote:

I'm seeking thoughts, insight, tips or tricks relating to portable line
boring. I have a backhoe, and when it was built, LBJ was president.

I didn't verbalize really good so here is a picture of a home made boring bar.

http://www.garage-machinist.com/usen...Boring_bar.jpg

The drawing is using a 1" shaft, 1/4" HSS lathe bit, and tapped for a 5/16 set screw to
push the tool out.

You don't need fancy bearings. Plates with close fitting holes tacked to each side to
center bar, use lots of lube.

Look at Bill Marrs link, specifically,
http://www.cpmt.com/docs/bm/BB5000%2...%20Machine.pdf

You don't have a big pin hole so the cutter head shown isn't going to work but I think
what I drew would work for you.

Wes