I've researched the Mud forum, SOR VIN charts, and other threads -- I found similar questions, but no clear connection.
I have a 1977 with a VIN door plate and frame number that match - both look to be a July 1977 build -VIN FJ40 253568.
I have a very similar problem as described in
2H-engine number / building year
unfortunately the thread wasn't really helpful enough to see what that means for my engine.
Also for me, I have an Engine that was put into a different body.. In my case a 2H engine is sitting in a...