I couldn't agree more. The data plate reads c 500 y180 stamped over with 200? I have the s/n and lot # in my truck the model year is 1979 I can't remember the numbers and it's late I'll try to remember to post the S/N tomorrow again thanks for the help!!!!! There is no modification other than now only having pressure to the bottom of cyl rather than at the bottom and top. The top pressure line in the cyl is only plugged at the line and IMO hyd pressure to the top and bottom of the cyl when lifting can't be safe. The rebuilder is re doing the cyl. The cyl in it is a clark cyl but a single no longer a teloscopic this was apparently changed sometime in the past by who? After the rebuilder does his thing I will operate the machine in this mode as it can do no harm to the packing and check it's operation for safe and proper operation and the guy who bought the truck off fleabay is in touch with the seller so we will see?