The last 510 gassers used the GM 350 ci.in V8. My family purchased one around 1975. We would have rather had a diesel, but would have had to order one. Combines of all brands were evidently scare in our area of Ohio at that particular time so we bought the 510 gas to ensure we’d have a combine. It was a great combine for us. The 205 is certainly a cute little machine.
The 350 was the replacement engine for the older ones as well. GM stoped the the 327 in 69 I believe. The combine engine was the "industrial" version. Most had steel cranks,small valve heads and small lift cams. Always wanted to run a 510 with the governor un hooked just to see what would happen. Lol.
Agreed that 205 looks pretty neat.