I hesitated to answer this one, cuz the 235 lifter question is tricky. Lets set the way-back machine for 1953....
In '53, chevy came out with the full-pressure 235. It was available in '53 sedans with powerglide. It had aluminum pistions, full-pressure oiling, and solid lifters. In '54, this motor was carried over and used with a 3-speed standard. The powerglide models were given hydraulic lifters.
In late '55 the 235 was redesigned. It was given a better water pump, non-shim main bearings, a different oil pump, higher compression, a 12 volt starter, and all blocks were drilled for hydraulic lifters. Some engines used hydraulics, and some solids. 55-57 is a gray area for which lifter was used with what body/tranny/rear combo in sedans. Typically the standards had solids, and 'glide cars had hydros. In '58 they started putting hydraulic lifters in most 235 sedan engines, regardless of tranny or option packages.
Sometimes when a 55-62 solid-lifter engine was rebuilt, hydro lifters were substitued in (with cam change) to reduce the need for valve adjustments. Then the engine was repainted whatever color: Blue, Gray, F*rd Blue, Chevy Orange, black, pink, or whatever spray can was lying around. That may explain your engine paint, as my '54 Bel-Air 235 is supposed to be blue too. (and will be again shortly)
Your valve noise problem may be due to lifter bleed down during high-speed runs. If you've got hydro lifters, they could lose their oil charge and start making noise, until the engine slowed down again and the lifters could recover some oil. I think this was a common complaint with the 235, especially in hopped-up road jobs. (I love vintage hot-rod slang) Of course if you've never adjusted them, they could be out of adjustment too.
The short answer? The only way to tell for sure is to pull the side cover and have a look at whats going up and down in there.
have fun,
chip