I don't know if this is much help, but I'm in the same boat with my 54. I noticed that I can push down on my rockers against the pushrods approx 1/16 to 1/4 inch telling me that I've got hydrolic lifters. I haven't had a chance to try it yet but there is a good description in the stovebolt.com faq page scroll down to how do I? Seems pretty detailed. I'm about to do it mysef because I'm supposed to have solid lifters. carnut.com has some good spec sheets for various 235 cars and that should get you close.
