Hi Jay, Just running the threaded rod through (Which ever way you go)
with whatever force it may take, will certainly not give you the same
good results as using a Tap, or Die (And Tapping oil).

Using this previous technique will possibly make matters worse. I'm
sure you don't wish to get this rod seized in the base, then wind up
resorting to pipe wrenches in frustration to try extracting the Rod.

As another poster has mentioned, the bottom base plate is supposedly
removable from the LX-90 (I didn't realize this, as I never owned a late
model Meade SCT) I'd remove the base plate, and cart both Base plate,
and Threaded Rod down to a local machine shop, leaving the scope at home
where it is safe.

You'll probably be in, and out in 5 minutes, and many of these shops may
not even charge you a red cent. If they do, I'm sure it won't be any
more than $7-10, and you'll have peace of mind knowing that the job was
done right.
Mark D.