Magnafluxing is only applicable to ferrous alloys but there are dye penetrant systems in wide use for aluminum alloys. If you're not familiar with their use, I'd recommend avoiding the risk of misinterpretation and having a professional do the test on your pistons and other aluminum parts in question.

We're all entitled to express our own opinions, and I will not be sucked into a continuing diatribe about the benefits and occasional flaws of PAC membership. But my own experiences based on 45 years of membership couldn't possibly be more diametrically opposed to those expressed by another correspondent. Like most organizations, what you get out from it is proportional to what you put in; hence nothing in, not much out. Great events both on the regional and national levels have yielded great camaraderie and many life-long friendships. With an occasional hiccup here and there, the ?Packard Coromorant? publication has deserved the many accolades it has received over the years. Is the club perfect? No, much like ourselves it has its warts. But to imply that it has done nothing to promote Packards and hobby in general is simply incredulous.

If in fact you are going to use your old pistons (after a careful examination of course), you might want to review some of the older engine-rebuilding texts on piston reconditioning. Checking piston ring grooves for wear (especially the top ring) and recutting where needed is one item (the standard ring would then use a shim). You might also consider either knurling the piston skirts or using piston expanders to try to compensate for the extra clearance; while this is certainly less satisfactory than reboring and fitting new pistons, it was a common-enough practice years back.

I don't disagree at all, they didn't call it "the last days in the bunker" for nothing, probably pretty hectic times. But doesn't it make for fun going back into time and trying to disect all this?

No, that's not what I'm saying. There are generally two different engine numbering systems in use, though not all engines I've seen have them both. There is the ENGINE SERIAL NUMBER which is the same as the vehicle number and usually stamped on the flat below the oil filler tube though sometimes elsewhere, and there is the UTICA PLANT number which, up until May 3 of 1956 or thereabouts was stamped on the right rear exhaust flange.

If you're looking for just a serviceable engine repair and not a true rebuild, I don't think the 0.001-003 taper would be a problem, but of course you have to hone to get the new rings to seat. Just recognize that you won't have the fit that properly sized pistons and bore would give. As to rings, I wish I could be more specific, but those 4-ring sets are or were available not too long ago, why not Google "piston rings" and see what you get. I remember a parts depot, on the West Coast and perhaps the Pacific Northwest, that had them.

Some of us are old enough to remember when "scotch" brand tape meant that it was manufactured by 3M (Minnesota Mining and Manufacturing). What happened there is that 3M lost the rights to the exclusive use of the trade mark "Scotch" because they were lax in enforcement against infringers. The same loss of rights can occur with patent protection if you allow others to infringe long enough without attempting to protect your rights.

PackardV8, I think perhaps you're confusing the engine number stamped up front by the oil filler (also the VN, stamped at the time the vehicle was assembled) with the Utica engine plant number applied when the engine was built and before it was shipped to Connor and assembled into a car. These numbers are sequential and begin with a prefix to indicate whether it's a Clipper, Patrician/400, Caribbean, or Executive motor. An additional prefix was used if the engine was equipped with a standard transmission flywheel. These #s, as with the transmission numbers, are the keys to when various changes were made in production. According to Packard's Service Technical Bulletin 56T-20 of May 3, 1956, "the Utica Plant engine number is now stamped on the casting at the same general location as the engine serial number and not on the right rear exhaust port flange as has been the practice previously".

As to the oil pumps, the fact that Caribbeans were late production doesn't mean they have late engines. My own Carib is a late car (#254), and yet it has a very early Utica plant number (#137), ad a late casting date, yet also a very late Ultramatic number (#509). The Ultramatics, also made at Utica, also use a prefix number to differentiate which series of car the transmission was intended for. The "C" prefix is for Caribbean. All of the above has at best of curiousity value, but it does shed some light on how Packard rotated inventory received from Utica into the production line.

As to the door jam courtesy light switches, the very first 56th series cars used two switches (presumably one for the interior courtesy lights, one for the side running light?), then they switched to a single with a plate over the unused hole, and the last bodies only had a single hole and switch. This is somewhat documented in the 1956 Caribbean roster data published by PAC back in the 80s I believe, the same report which indicated which cars had which equipment, like which had the underseat heater, seat belts, rear radio speaker, etc. Lots of interesting trivia for the Caribbean fan.

Its also interesting to see how many convertible Caribbeans came with wire spoke wheels, I forget the exact number but it was less than a dozen as I remember.

One of the many Caribbean items that has eluded me to date is the correct paint color for the steel wheels. If I had to guess, I'd say the middle color.

Postscript: Let me add a bit more. The changeover to the plugged relief valve in the oil pump occurred in Caribbeans at Utica #C1400, meaning that of the 500+ Caribbean engines, the first 400 were not so equipped. As to the double door jam switches, the earliest Caribbean I have data on (a number less than 10) has the chrome rather than gold mesh behing the grille, and has both holes for dual jam switches, with on plugged off. The prototype 56 Caribbean convertible, made by the factory by modifying a 1955 Caribbean, was fairly well photo-documented some years back. It had dual door jam switches if I recall correctly.
As to the Utica engine plant prefixed, "A" was for the 5640 with Ultramatic, "AA" for 5640 with standard shift; "B" was for the 5660-5670, "BB" for the same with standard shift; "C" was for the 5688 and there was no "CC" code for standard shift, and "D" was for the 5680 and "DD" for 5680 with standard shift.

Robert, if I had the documents I'd be more than glad to make you a copy, and I would have probably donated them to the PAC years back. But I've got to contact another person who knows yet another person who has them, and I feel I've worn out my welcome for these favors at this point. Perhaps the fellow who owns them will someday donate them to PAC or the Studebaker Museum, or some other public site, or advertise the fact that he has them. I don't know the reason for his secrecy about them. Sorry I can't help.

But while on the subject of 56 Caribbeans, myself and several other owners have been trying to gather information on these cars, and perhaps you be kind enough to provide that info to me via a PM. The data we've been gathering, for distribution to all those who contribute includes: Car #, Build date, Shipping date (June 25 for your car), Delivery date, Engine casting date, Cowl # (thief-proof number), Utica engine# (right rear of block, usually), Utica trans #, Oil pump variation, Door jam switch variation (one or two per door jam, with or without a blackoff plate over the second one), and Grille mesh (chrome or gold).

I got a copy of the production and shipping orders for my 1956 Caribbean convertible, and have been involved in getting them for several others thru a fellow PAC member. They were obtained from a private individual who has them but does not wish to be identified as a source for these documents.