7/16-20 is UNF (United National Fine) thread. Get a die nut and run it over the studs to clean them up if you have not done so already. THe gasket sounds like a compound material which I have used successfully. The copper side goes to the head, the bottom I would assume would have a lapped in burn ring to go to the head side to get the seal between head and block. Have the head shaved if needed to make sure the are no warps, highs or lows so it is perfectly flat using a flat edge and feeler guage to find any highs or lows.

I also recommend going back to vacuum. Once you have it working soundly it is a great system. I support the comments regarding electric pumps and issues regulating the inline fuel pressure feeding the carburetor. These 1929 Series 6 are Packard at their zenith, others who have them hold that view.

These parts were possibly made by the late Henry Yeska. I understand his son may be continuing his efforts. Try 484 764 6351.

Please publish if you are successful. If you are given an email address also please publish that.

This open car is a 443 to me. Drum headlamps last year 1928. The Series 6 from August 1928 saw the new style headlamps.

A 640 the car next to it a 1929 Cadillac Convertible Coupe with a set of nice Buffalo wire wheels.

A Series 640 August 1928 to August 1929.

Thanks

I live in Australia, is there any email contact ?

Does anyone know of a contact for the Henry Yeska reproduction parts ?

https://www.ebay.com.au/itm/142865380972

This is the correct size

I recently pulled the head of my 1929 to clean it up and replace a head gasket. Naturally I cleaned out the head, block and radiator. One thing I did do was replace the thermostat which had obviously seen its days.The replacement was made by Gates. I am running at 160F to 180F and all is happy. I am running a straight 20W50 grade oil