stewbud,
the 848 & 850 heads were installed on 235's & 261's ( respectively ) at the factory. many were swapped over the yrs. & will work on either engine. the 848 head has a smaller combustion chamber resulting in higher compression & better performance.
235's & 261's shared the same oil pan. a 216 oil pan will not fit most 235/261's. the bolt pattern was different & it was equipped with troughs for the spray nozzle jet lube system. i say most because the early 53 powerglide, 54 & 55 1st series truck engines did have the same bolt pattern as the earlier 216's. if all of that trough assembly was knocked out i suppose it would work on those earlier ( 53, 54, 55 1st ) 235 & 261 engines.
robert
