bob, the if you are using the original 51 tranny it won't bolt up to the 56 bellhousing. car trannys had a different bolt pattern thru 54. the 56 235 will bolt to the 216 bell housing just fine. the front & rear of 216 & 235 blocks are the same. the starter flywheel & clutch from the 51 will all fit the 216 also. the early 6 volt starter also works quite well in a 12 volt system. ( cranks real fast;6 volt starter actually had heavier windings, done it alot believe me it works.) if you have to use the later 12 volt starter you'll have to use the 56 flywheel & clutch. when the change to 12 volt was made they changed tooth count on the starter drive gear & fly wheel ring gear. the drive gears will not swap between 6 & 12 volt starters either.
so the rule is: early starter-early flywheel. late starter-late flywheel. either starter & flywheel package will work behind the 235 & in the 51 bellhousing. ( however larger truck flywheels won't fit in the early bellhousing ) i think 52 is when they went to side engine mounts. if the 51 is the same as my 50 you'll also need to put the front mount plate ( it's behind the timing gear cover ) from the 216 onto the 235. all this info. & more about swapping the full oil pressure 235 into the 53 & earlier cars & trucks is available from the stovebolt engine co. & patricks antiques. there are links to them on this site & most of this stuff is in our tech tips section. have fun!
robert.
