Let's see now, the GMC/Cad combo was used by a plumbing contractor with 61 crews to carry blueprints and consult with foreman on a daily or weekly basis. It wore out the original 472 engine which was then rebuilt and wore out again. The present 500ci engine has around 100k miles on it so the total has to be close to 400k miles and the chain steering has required ZERO attention in that time. As far as cab to frame flex the chain is way more forgiving than the rigid steering tube/shaft solid at the frame plus solid to the dash and brace rods. If you have a lathe like our big old 1941 Monarch just anchor one end of a 3/4" steering shaft and use two sprockets with chain to the head stock. Leave the tail stock loose on the ways and put the lathe in low gear. It will wind the steering shaft up like a pretzel and unwind it back again as many times as it take to destroy the shaft and the chain will be unfazed. Believe it or not we didn't just fall off the turnip wagon with just a hammer and pliers to work with. Now it's all computer design but in the beginning we built them starting from chalk marks on the floor so frames, suspension, steering, roll centers, CG, Ackerman, anti dive, etc are familiar to us.
Last edited by SWEET; 04/21/2020 8:20 PM. Reason: Family editing
