Re: 1956 Caribbean hardtop options on a Four Hundred

Posted by Owen_Dyneto On 2016/3/24 13:53:57

Almost certainly the changes were done by a dealer (or later) and not at factory.

But in the absence of a build slip no need for any uncertainty, there is a way to determine if (a) it's a bona-fide Caribbean engine (as opposed to a 400 or other engine with dual carbs) and (b) if the engine is original to the car. Crawl under and check the Utica Plant engine code; if it really is a Caribbean engine it will have a Caribbean engine code prefix "C" rather than the "D" for the Patrician/400 engine, "B" for the 5660 engine, or "A" for the 5640 engine.

The Utica Plant code if you're not familiar with it is the engine code assigned when the engine was built, a different prefix letter for each engine series. It's located on the passenger side, far rear just below the cylinder head, and is (barely) visible from beneath the car. If you find a "C" prefix it doesn't necessarily mean the engine came with that car but rather only that it's a bona-fide Caribbean engine. Then if the engine# up front (5687-XXXX) matches the vehicle # that would tell you that it came with that particular car.

Just another note on the Utica Plant engine numbers, a double letter prefix indicates an engine built with a manual transmission, for example AA and BB designate a 5640 and 5660 with standard transmission. There were no CC or DD designations so no factory standard transmissions on these two car lines. And the Utica Plant numbers for the Ultramatic transmissions follows the same pattern, prefix A and B for the two Clipper lines, C for the Caribbean, and D for the 400/Patrician.