Hy patace, welcome, there are actually two different 55 trucks, the 55 "A" or first series (old body style) and the 55 "B" or second series (new body style), they are quite different from each other engineering wise. Grigg has made a lot of modifications to the early style chassis, but a lot of the info can be helpful. Search for his posts or search for power steering conversion, hope that helps.
