Hi Denny; Looks like you did your homework. The full pressure 235 actually became available in '53 on powerglide equipped cars and another important difference on these "later" 235's was the use of insert rod bearings instead of babbit bearings (the '50 - '53 235's still used babbits).
This new design, with some minor refinements was used through '62. Patrick has some pretty good info on identifying the late 235's (I think it's on his website, if you have one of his catalogs it's in there too). I'd like to see a detailed chronological list of the changes on these engines too.
