Well Jon,
The first thing to look for is how the valve cover is attached. If there are two acorn nuts holding your valve cover on, it's
probably a 216, if the valve cover is attached to the head with four screws than it's
probably a 235. The exceptions to this rule are the babbited splash oiled 235's manufactured 1941-52 which have the same type of valve cover as the 216, and the insert bearing full pressured 235's manufactured from 1953-62 that have been altered to use valve covers with the acorn nuts and so appear more original.
I will assume that you are looking to tell the differance between a 216 and the desirable '53-62 235's. For that information I will defer to
Patrick\'s Catalog:
A. Simply checking the style of the water pump will take care of about 90% of the prospects. If it has a pump whose entire body is below the head casket surface, rather than half on the block and the upper half in front of the head, it's gotta be '55 (2nd) through '62. You've found it. The search is over. Disregard any of the next criteria.
B. Check the rocker cover ("valve cover"). If it's held on with four (4) screws (2 on each side), it's a '54 through '62 and the right one. Look no further; you just scored .
C. Walk on by any engine with the tall pushrod cover that surrounds the spark plugs. It is a "babbit pounder".
D. Also eliminate any engine with the little, tell-tale triangular plate and curved oil line in the middle of the driver's side. This tells you it has the dreaded dipper rods and splash oiling. The driver's side of the engine you want is "clean" (no plate or line).
E. Disregard any engine with the studs through the rocker cover, except one: the '53 P.G. (first year); but, it will be without the above plate and line, too.
F. Want to pinpoint engine I.D.? On the block above the end of the starter will be an initial (A-L), followed by either (2) or (3) numbers. The initial represents the month: the numbers are the day and year the block was cast. Now, then, no more guessing!
