You'll see "more" at the right at the top of the post you want to link.
Click this, and then at the bottom of the drop-down you'll see "permalink"
Click that, copy and paste the unique URL for that post into your reply.
Or you can say -Jeff's post here- highlight THAT, and use the link (chain) button above the reply window to turn -
Jeff's Post Here- into a hyperlink.
Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.