This shop doesn't know enough about the TIB Ford suspension...
Yep, I agree completely with that. With these beams installed your suspension (beams, radius arms, springs, etc.) should be in exactly the same position, assuming that's the only thing you changed. The change, where your drop comes from, is that the steering knuckle (and mounting points on the beam) is physically moved three inches higher in relation to the rest of the truck. You should still be able to align the truck with stock alignment cams. Likely scenarios in your case are (1) the PO of the beams had more drop and his eccentrics are still in the beams, or (2) when you installed your eccentrics in the beams the position was not kept. For the first if the PO had adjustable cams the alignment shop should be able to align with them, if not they may need to be changed for adjustable ones. If the second they should be able to align it no problem with what's there.
The eccentrics (or alignment cams) can be had up to 3.5* and can get them from Carquest, O'reilly's, Advance Auto, and I believe NAPA might carry them as well, with Carquest being the cheapest, at around $14 each IIRC.
As mentioned previously there is a thread in another forum about this. I'll throw out a little more info though. There are actually two types of eccentrics available for these. There are adjustable and non adjustable. With an adjustable if you buy say a 3 degree adjustable it's two piece and can be adjusted for any degree from +3 to -3, IIRC it can also adjust caster to some extent. Non-adjustable are just that, say you get a 3 degree of this type, it can only be used as a +3 or -3 degree, nothing in between without affecting caster. Install an adequate range (biggest available) adjustable before getting an alignment and no other eccentrics should be needed, ever.They are a bit more expensive though, I think I paid around $60 for both 3.5 adjustable for first gen that I won't be using now. If you choose to use the cheaper ones you'll have to get it put on an alignment machine first and they will either tell you what size you need or do it for you.
IIRC you can get up to 4 degree adjustable from NAPA (only for the 89-97 beams), the part number for them is floating around here somewhere. If I have to replace the bushings that SVT put in these beams that's what I'm putting in.
JoshT bought my beams and coils, and I'm sure he will have great satisfaction with them...
Got them cleaned, removed the flaking powder coat, and shot them with some Semi-Gloss Black Rustoleum. I know it's cheap stuff, but I used their Professional line hoping it might hold up a little better. This isn't a show truck it will get hit, chipped and scratched, this way when it needs touched up all I gotta do is buy a can at home depot and spray away. Still don't know if I'll be using the springs, going to wait and see how it looks with stock once the V8 is in and settled.
Now if the damn rain will go away they'll be getting installed. Got one beam and radius arm in place last night once it cooled off enough to work on it. Just need to install the other side, and springs then I'll be able to get it sitting on 4 wheels again. So...
Rain, rain go away, come again when I'm at work some day...
Doubt it'll work but it was worth a shot.