Dwight Heinmuller sells a few nice covers and he is easy to work with:

https://www.packardparts.org/products/car-covers/

I thought Kanter used to sell a nice one, but I don't see it listed now, but their website has been redesigned and a lot of things that you used to be able to find you cannot. Maybe it's still in the printed catalog.

Reading your post, I am still not sure what you are starting out with and what you are finishing with. Maybe it would be good to start there with a clear delination of both, and what you think your options are.

If the original car still has it's manual transmission, especially if it has overdrive, I might consider starting with that, just bolt the new 327 into the old tranmission. Otherwise you have to change steering columns at the very minimum, not simple nor fun. Also in this case the original axle should have the correct ratios.

It's not clear to me why you'd want to switch axles in any case.

Ross Miller, for one, is very complimentary of the Packard 3-speed+overdrive setup. It has nice gearing for the highway and good acceleration, something that cannot be said as much for the Ultramatic.

If you really want the Ultramatic, you probably want to save the manual transmission, steering column, axle, those can be sold to someone who would want to switch from Ultramatic to manual.

If the engine is truly from a 1950, the engine mounts should be the same, so it should swap in nicely, I think.

That's just the standard tail shaft extension from the 1951-54 ultramatic.

That might be a cooler for 1949-50. It doesn't look like the standard 1951-54.

Before you use a cooler, you should get it tested, they can leak internally and that's bad. Max Merrit and Kanter also have rebuilt/tested ones available.

The main thing about the rear axle is the ratio.

Look in the service manual on this website, it has all the rear axles and ratios. The main thing of course is (depending also on the tires used) is the revs/mile. The revs/mile for a 1951-54 Ultramatic is usually rather low (geared low) because as essentially a single-speed transmission, you needed a high rear axle ratio, e.g. 3.54:1 so you could get some reasonable acceleration. That said, there was some variation.

Max Merrit has rebuild kits and parts available as well.

Max Merritt 1956 Ultramatic Rebuild Kit

My thought - if it idles with the choke closed, that means it is getting enough fuel to the carb (because it WILL idle).

So there is something clogged in the carb itself. Might make sense to take the carb off and blow out all the passages with carburetor cleaner.

IF the car has a filter, it would be on the line that goes from the fuel pump to the carburetor, at the inlet to the carb.

You should have a rubber hose for part of the line to the carb (shouldn't be a hard line the whole way becaue the engine is on rubber mounts). So you could replace that rubber line with a clear line - if there is fuel in that line, the carb is getting fuel. It doesn't need a lot to idle!

There are other folks who make rebuild kits and/or rebuild fuel pumps, but both Max Merrit:

Part# 98730, fuel pump rebuild kit, double-action
fuel pump rebuild kit, double action, Max Merrit

and Kanter and Max both offer rebuilt fuel pumps on an exchange basis.

Kanter Packard Parts Page 1948-1954

Kanter Packard Parts 1948-1954

Best to call either to make sure you are getting the correct part.

There are two likely possibilities:

1) The first is that you didn't check the clearance correctly for that particular tappet after you (presumably) ground the valve seats. Now the clearance is too tight for the lifter to pump up. It should be 0.030 to 0.070 cold using a gage. There were instructions on how to do this in the Kanter kit with the new tappets using one of the tappets as a gauge. A gage is also available from Pacific Northwest Packards, or you could use one of your old tappets (slightly risky).

2) The second is that particular tappet is bad for one reason or another. It could be dirty, but if it works at cold but not at hot it is more likely bad than dirty. There is a video on "Speedwell Garage" Youtube Channel where he discusses testing tappets. Ross has also on occcasion tested tappets for one. Since you are far in Australia that might be difficult. Ross made a few tappet testing tools or you can make one yourself.

Also there has been much discussion on this website using the term "noisy lifters".

A lot of folks just pin the valve open, it is rarely needed the way these cars are driven today. That would be a good interim fix and help you to troubleshoot if you have any other problems.

If you look up above Jason from Advanced Electrical Rebuilders will rebuild yours for $75.

Also see Ross' note below about the spring.

You might also call up Buchannan Auto Electric in Oakland, info is in the Directory under "Packard Services"