Ok-
Ideally, if you were to find a 1979 and later front axle assembly from a 40 series, you would get the larger pattern knuckles and have disc brakes that would swap into the truck strait-forward. You would need to install your differential from your front axle, along with the axle side gears from the 1979, as you will have a 4.11 gear ratio and the 1979 would have 3.70, also, you would need to swap out the axle side gears from the differential, as your inners are likely coarse splined, opposed to the 30 spline versions that were used from 1968 and later. The differential area of the axle housing stayed in the same position, so you will not need to concern yourself with drive shaft alignment issues.
Another option is to find a front axle assembly from a 08/75 to 12/78 40 series. This will bolt in as well as the previously mentioned would, however, you will not need to concern yourself with swapping out the differential as the gear ratio will be 4.11, the same as what is in your truck, provided it has not been messed with. The drawback to this axle is that it has the smaller knuckle studs, 11mm and smaller bolt pattern, which if you are not going to be going the direction of a spring over and hysteer, is not that big of a deal.
However, if you see yourself building a truck that will include a spring over and hysteer components on it, I would avoid this axle configuration because of the limited availability of hysteer components, and the general weaker, smaller stud pattern and diameter, compared to the later knuckles.
Another option is to find a known good front axle housing, post 1967 that uses the inner axle seals, opposed to the solid bushing that your front axle uses, and then get the outer knuckle pieces from a 60 series and build your own disc brake axle assembly. While this may sound intimidating, it really is not that difficult of a proposition; just time consuming. There are many threads in the FAQ concerning Toyota mini truck/60 series disc brake swaps to use as reference material.
No matter which direction you go, I would suggest getting a Factory Service Manual/Chassis and Body Manual to use for reference as well.
Odd that you are having trouble getting a hold of anyone at Classic Cruisers. Merle always seems to be there when I call. Has been that way since 1993. Perhaps he was at SEMA or some other trade show. He is involved with a number of different projects. Something else to try would be the Colorado/Rising Sun section out here. I am sure that someone out that way has an axle, or knows someone who does. Proffits may have a front axle assembly as well. Jeremiah is another very knowledgeable Land Cruiser contact in Colorado.
