88 Xj; Water Pump Bypass Tube Choices?

I believe it will but am not sure. IIRC that is just a 1/2" NPT thread. Dorman makes a replacement for it too; their part number is 56398 and it's generally available or can be ordered at local parts stores. AutoZone has or can order it for $15 and it is $8 on RockAuto. I suggest using PTFE thread sealant paste when installing it.

Some have had success using regular threaded brass NPT pipe of the appropriate size, a 90 degree threaded elbow, and a threaded hose nipple - all available in the Home Depot plumbing aisle, longer lasting, and more likely to be reusable in the future.

1/2" or 3/8" NPT sounds right.

Note from DJ
Take a look at this post.

Water Pump - Hard Line Pipe Improvement
http://www.naxja.org/forum/showthread.php?t=1075276
OP by Tryfan

I just reused the existing one on the old pump. It was a pita to take off, but worked on the new one. I would have bought a new one, had I known before tearing into it. It's worked fine so far. 1990 XJ w/4.0 Renix.