Current cap numbers: Echlin AL66 for Autolite, RR-100 for Delco. From Standard Ignition, AL97 for Autolite, and DR 196 for Delco.

Firing order is 1-6-2-5-8-3-7-4, same as almost all Packard and other maker's straight eights except the 1st and 2nd series Packards. The AEA tuneup chart is on PAC's website if you don't locate it elsewhere. Distributor caps are readily available new from almost any decent auto parts store, though you may have to wait for the next delivery. You'll need to tell them whether it's Delco or Autolite.

Rear wheel well clearance on Packards, from the bathtub era (or perhaps beginning with the Clipper body shell) thru 1956 is pretty snug and many of us have had the experience of deflating a spare to mount it, and then reinflating on the car. But an L-78 is really pushing the tire size, its the rough equivalent of 9:00x15 according to Coker's conversion chart. 8:00x15 was the standard size for your 56 Patrician, though apparently 8:20x15 was an option. Some folks have experienced front clearance problems on full turns with 8:20x15, and also with 235/75R-15s, though others have not. Tire sizes can vary considerably with different manufacturers and where the wheel well clearance is marginal to begin with, it creates the problem you're experiencing. For the alpha-series tires, my 1948 Custon 8, originally fitted with 8:20x15 as a factory size, just barely accomodated G-78s and even then you needed to jack by the frame and wiggle to get the rears on and off.

There may indeed have been a special tool for removing the tabbed locking ring, but I've never seen one or heard of one. Try a little PB blaster, and just keep tapping on the ears, alternating sides, and it should come free. Be gentle and patient, it's not a part I'd care to have to make.

Responding to an earlier question in this thread, 7:00 x 15 and 7:60 x 15 are from two entirely different tire sizing regimens from different eras as can't be simply compared. The 7:00 x 15 is a larger tire than a 7:60 x 15.

The "brush-on" engine enamels do indeed dry very fast and don't give a great appearance even on rough cast iron. You'll be much happier with the results if you thin them and add a bit of retarder to slow the drying. Even then, its not possible to get the kind of finish on stamped steel parts that we all want.

There has been a lot of controversy about the 48-50 engine colors, and you'll find LONG threads about it on the PAC website. Originally the judging standard was for gray as the 51-54 engines (except the 359) were, but a number of 48-50 engines, almost always the 356 engine, were observed in green that were without dispute original and not repainted and thus it appears that both colors were used, though I don't think anyone has ever sorted out just why some were gray and some green. PAC may have revised their statements about this, check their website for the latest.

Exhaust manifolds are best done with Eastwoods high temperature stainless steel paint which when dry gives the appearance of virgin cast iron as these were originally. I believe (not certain) that the intake manifolds were black and don't require a high temperature paint.

BTW, looks like your valve covers have been reversed, the one with the provision for the road draft tube should be the rear cover, not the front.

Actual dimensions for same marked size tires from different manufacturers can vary a bit, perhaps more than most of us realize. I don't have that problem on my Caribbean with the current GoodYear 235/75 R15, and didn't with the prior bias ply 8:00 x 15, but the earlier 8:20 x 15 bias ply tires did rub at both ends of the travel. 8:00 x 15 was the OEM size, and apparently 8:20 was an option though I'm not certain of this.

I'm sure that all the people who visit and exchange experiences and information on this site hold their Packards and the company that produced them in high regard. I hope they all manage at one point or another to contribute to the efforts being made at the Proving Grounds, it's a monumental effort for such a small group, and so worthwhile.

Please Mal, don't turn introvert or go shy on us now. I've left a pretty fair trail of bloopers behind me along the way.

Can't find my hammer, but the frame numbers for 55/56 are in the 4xx,xxx series.