The only difference between the pickup and the t-100 was that it was wider. There was not any problem with the suspension design of the mini, nor with it's load carrying capacity. The T-100 was still rated as a 1/2 ton pickup, just that it was a mid-sized package (fit 3 adults across - Toyota's attempt to compete with the Dakota and similar trucks). The interior design was the same as the mini's, just wider. The body design was the same, as was the choices of engines (which should have been changed).
However adding mini truck suspension to a T-100 frame does not seem worth the trouble, if it was, Toyota would have done it
So, what would be the trouble? Because I do believe they did exactly that. It is far more cost effective to use parts that are already in production, than to have to re-tool a plant to make a re-designed part.
