Busta1, First off, Welcome to Stovebolt!
On your valve spring question, below is a screen grab from a 1962 Chevy Master Parts Book. Shows the 1938-53 All (216/235) and 1954-55 235 (except Powerglide equipped - w/hydraulic lifters) used the same valve springs. The Powerglide equipped 235 engines for 1954-55 used the same spring as later 235's and 261's. Others with more knowledge about if the valve springs can be interchanged should be along soon to provide more detail and response to your question.
