This is what I've posted before on the benefits of the twin stick...hopefully you can use some of the info to sway you parents...
The advantage is to be able to operate the front and rear differentials independantly. I haven't operated it, or run it yet, my knowledge is solely from what I've learned on the lists.
These are some basic reasons why I chose to get the twin stick:
1) The ability to disengage the front diff in order to turn while in 4-lo when crawling;
2) You have a greater range of operating modes, i.e. 2-hi rear, 2-lo rear, plus same combos up front for front wheel drive;
3) If you break a u-joint on rear shaft...no problem, just put rear diff in N, and pull yourself with the front diff.
4) Shifting is easier...many EB's, especially J-shifts, are a PITA to get outa 4-lo. On my '77, I would have to "pop" the clutch in reverse in order to get the shifter out of 4-lo.
5) From a cost vs. benefit perspective, it's a relatively cheap, and simple upgrade at $150, cheaper if you can make it yourself...and there are web pages with specific instructions on how to do so.
6) I didn't think I could find all the parts that went to my original shifter 'cause I took it out over a year ago, LOL.
7) More levers coming out of the floor are COOL!
8) Chicks dig twin sticks!
It would be better to do the upgrade now while the TC is out, 'cause getting to the shift rails is a PITA unless you cut a big hole in the floor.
HTH
