Roger, the '53 235 Corvette engine originally used the same cam as the truck 261, and had solid lifters. The truck cam has a bit higher lift - which is why Chevy installed it in the Corvette engine, for a bit better breathing. As SS said, you can't use hydraulic lifters with the 261 truck (or Corvette 235) cam. Further, the '53 block (if that's what you have) may not have the oil gallery drilled to support hydraulic lifters, unless it was originally hooked to a Powerglide (and even then, I'm not sure about the Corvette blocks, which used solid lifters from the factory).
What's the number stamped on the machined pad just aft of the distributor? That can be decoded to verify the original service installation of the block.
Hope this helps!
