The motor mounts are always a concern. Years ago, had a buddy with a '63 Ford Unibody shortbox. Being the impetuous teens we were, we could leave nothing alone. A 460 soon found it's way under the hood, needless to say, the frame (originally designed for a straight six with less than 100hp) was not too happy about a 500hp big block. We welded those motor mounts in time after time. Being young and dumb, we never did get it right, but man it was fun! With weight in the back we could almost get the front off the ground! This was an instance where we had totally exceeded the capacity of the existing structure. Knowing what I know now, I would have boxed the whole front, and likely put a brace up and over the top of the engine. Is this necessary in the case of a 2.6, maybe but probably not. But, the motor mounts are definitely an area that deserves some attention.
If you would like, get me a front axle weight, we can WAG the load from the engine on the motor mounts, if someone happens to know the weight of the engine and tranny, that would help (but we can always just throw a conservative estimate at it). I will also need some spring lengths with center pin to shackle distances, and I can calculate some stresses in the frame itself. Using what we know of the stock ZU frame, I could design some stiffeners that would put the frame in a nice low stress region, to give it long life. I would be happy to help anyone who like to put a little engineering into their SAS. Maybe we could even come up with a nice canned kit like All-Pro has for the Yota trucks. <img src="/forums/images/graemlins/notooth.gif" alt="" /> Or at least some plans we could all share.