You're basically running a 100% custom setup now, so you need to make more custom modifications to make the angles match.
You have a '76/'77 frame, with the larger trackbar bracket.
You have an "Inverted-T" steering linkage, which was appropriate for the earlier frame with the smaller trackbar bracket.
You have a 3.5" suspension lift.
You have a dropped pitman arm, which (aside from having the wrong angle on the end) would have been too much drop anyway with TRO.
You have the tie-rod on top of the knuckle (TRO) so your angles wouldn't match even with a stock pitman arm.
The arm itself is not a big issue. Lots of members here have used the full-size truck arm on their '76/'77 EB's to correct an angle issue with the T-steering. But yours has other mods that work against it. I sell them for exactly the shorter drop they provide. But when using a FS arm with the wrong offset tip, you need to make sure your draglink has a head start by working to keep the angle to a minimum.
So your current options to at least minimize the issues are:
1. Raise the draglink to the top of the arm as was suggested. But this partially defeats the purpose of a dropped arm.
2. Put the tie rod back under the knuckle. This is normally how many '76/'77 owners get good steering after a lift and having changed to the T-linkage. Again, going away from the advantage of better angles, but at least making the two bars more parallel.
3. Lower the upper trackbar mount. Not as desirable as a riser with your TRO and probably needs to be custom.
4. Add a riser and use whichever hole works the best. You won't necessarily be able to go by instructions, as nothing is stock with yours anymore anyway.
Personally I like the idea of the riser the best. If absolutely needed after the riser, an EB specific arm will lower the draglink another inch approximately to where you can match the trackbar angle if needed. And at the same time it would get you an even shallower angle on the draglink. Shallow is better up to a point, but it's all about keeping the angles reasonable AND keeping the two links parallel.
Good luck. But more than luck you're going to have to do mock-ups both in your head (but with tape measure handy!) and physically (more parts, more money, but fewer headaches) until you find just the right combination of parts and design to get the best of both worlds. Low as possible angles, and parallel angles between the links.
Paul