The only pictures you will be able to get are the parts catalogues and workshop manuals.

Mark, what pictures are you looking for?. I have a '37 H8 sedan, mostly original under the hood. I can take some pictures if you like.

Mostly I was hoping for drawings that showed dimensionals of block, head and other main components. I’ve looked at the 34-37 mechanical procedure book and the engine picture cutaway looks to be the six cylinder but would have thought the eight cylinder would have been there too.
Guess the only way to get parts once and if needed is to ask the club members or reverse engineer. I’m sure Hudson engineering had detailed spec drawings but amc or Chrysler pitched them in the past years. In working for a large industrial company, our engineering drawings till we digitized were everywhere imaginable. Bet Hudson’s were in a box till they were not.

You are correct; most of Hudson's records, drawing files, letters etc. were thrown out at the start of the Nash-Hudson merger.

The cross-section of the six would be similar to that of the eight.

The parts manuals are very helpful, as they give you not only the correct part number, but also give you accessory information (often) as to the size and number of bolts holding the components to the body or engine. There is also a cross-reference manual from about 1950, which shows (by part number) which parts interchanged into later or earlier models of Hudson.

As to finding parts, I would suggest you work up a complete list with photos or drawings of the items, and send this to the many Hudson parts vendors which are found in the WTN. Of course there are many non-Hudson antique parts vendors who would have parts as well, though these tend to be engine parts.

For parts that are very difficult to find, you can develop a relationship with others in the Club who own similar cars to yours. They'll be in the same boat as you. Sometimes they can help you locate more obscure parts, or they will know if there are any interchanges with modern cars (or with vintage cars which were much more common than Hudsons). In extraordinary cases they may know of someone who has reproduced a hard-to-find Hudson part, but who has not advertised it (thus few people know where to find it).

Your probably correct Mark. We have a few 8 cyl. engines on stands right now, but I think your looking for exact engineering dimensions ,correct?. It would be cool to have those measurements for reference, online. As you probably know, Hudson introduced the 8 cylinder engine in 1930, with a 2 7/8th's bore changed the bore size a few times, until 1934 was 3" , still having a 4.5 stroke. In 1937, they changed the intake and exhaust configuration of the block to allow much better flow, was still splash lubricated, keeping that design until the end of use in 1952. From '37 to '52 the only modification were manifolds, carbueration, and vacuum advance in '48 , adding a little timing/efficiency. Thru this period, especially early on, the HP ratings varied, ending with 128HP.
A side NOTE : I have personally stress tested numerous splasher 6 & 8 engines! I think with everything these engines are and are NOT, they had a purpose. As many will and can tell you, some were good, some not so good! When these engines are right, they work and perform fine, and have an exhaust note like no other!. I can testify that a good running 8 cylinder engine can run just as good as any 262 or 308, in their power range- 30-60 MPH. The full pressure lube Hudson 6 cylinders were very dependable by comparison to the splasher engines, but the 8 cylinder engines worked good in the earlier cars. The 212 splasher engines worked very good in the Terraplanes. I have also personally witnessed and watched "Terraplane Kelly Hinegarner" run both a 175 and a 212 engines in his cars WAY beyond what they were every designed for!!