Early 1968 K1500 Manual to Power Steering

[1968k1500]

Looking for a way to put power steering on my early 1968 K1500 utilizing off the shelf parts with little or no modification.
I recall finding a kit from a company or a website offered, but since has escaped my memory. Any help would be appreciated!
It's a fairly STOCK truck, the manual steering box is old and just failed. At this point I'd just like to have power steering.
I don't mind using a box out of some other application... I just don't want to modify the vehicle AROUND the steering! Drilling a couple of holes is one thing... cutting, replacing, fabricating the frame are options I do NOT want to consider. I'd like it to look as if it could have come that way from GMC. I'd like to be able to service and replace parts in the future.

With that in mind: I tried using a steering box from a 1968 1/2 and newer 4x4 truck. It would not fit due to the following problems:
1. Newer steering box has a bulge in the casting toward the frame side, beyond the plane of the mounting surface. (Spacing the box creates alignment issues with inner fender and steering shaft.)
2. Frame has no relief to accept this bulge. (The newer trucks do)
3. Original box has only three (3) holes in which to mount the box to frame. (newer box has four (4)).
4. Only two of the holes in the frame line up to the newer box... rear upper and rear lower) in which case puts the new box in an extreme angle to the steering shaft, and in the way of the leaf spring. By the time the box is mounted with these two rear holes, the fourth (front lower) is so out of alignment it wouldn't mount to the frame, (below the frame rail).
I would consider putting crossover steering on the truck... however the same mounting issues arise... 1968 1/2 and newer 2x4 and 4x4 boxes mount using the same holes! Unless of course there is another box from some other vehicle.
Thanks for taking the time!