They use different pistons. The TRA-10D uses a DB-230-1, while the S-8D (and TR-10D) uses a DB-230 (no -1). The latest connecting rod for the TRA-10D is a DA-83 (no A).
Must have slightly different wrist pin location?
There are a BUNCH of DA-83A 10,20,30 rods on ebay very cheap but not a single DA-83. Be careful and look at the pictures of the actual connecting rods. Every one of them that I looked at has the A.
The connecting rod that I pulled out of my TRA-10D is a DA-77. I think that the replacement rod that I got off of ebay for my TRA10D was a DA-83. I kept the original box for it but I think it's up in the shop. I got it for $20 plus shipping.
The blocks are identical. If you can get a CA-84 crank and DA-77 or DA-83 connecting rod and a DB-230-1 Piston you can convert an S8D to a TRA-10D.
Wish that I had a chart with the newest part numbers. Trying to find NOS parts with the older part numbers leads to dead end searches quite often.
Wisconsin engines are my favorite. I picked up these from an auction 16 or 17 years ago. Can't remember exactly when. They are dated September 1980 and they show technical specs of all Wisconsin engines up until 81. These came from an old Wisconsin engine dealer that had closed down many years ago. They would have been under a piece of glass on the counter. I plan on having them professionally cleaned and framed as soon as I get ahead of my bills some time this year hopefully. They will look awesome Framed and hanging up in my shop. They are made of Vinyl. They are still ply-able but are getting a bit brittle. They were folded up in one of the old Binders that I bought.
I know a fella that is really good at cleaning and restoring old Vinyl prints but he is a bit pricey. Actually it might be cheaper to have him scan them and print out new ones but they are only Original once. I've seen some some amazing stuff come out of his Vinyl printing/cutting shop over the years. He's really good.
I have parts and service manuals for quite a few small engines, Including a fairly rare Kohler K7-2 and K12-2 shop/service/parts manual printed in September of 1956. That thing is really really neat. The illustrations in it are IMO works of art that any small engine nut would enjoy looking at. Most of my parts and service manuals are quite old.