My 55 G.M.C. 2nd series ex Navy, fire dept, has a 2speed rear axle. There is nothing on this truck to indicate it came with one as built.The axle has a number on it CL1110 I wonder if anyone can tell me from this number what it is?(Ratio or Year) If this axle turnsout to be decent or in good usable shape, I'll want to look for the rest of the parts to make the truck a two speed. Any help at all is great. Thanks, Dave H.