Picked up a 261 for my 3100 the other day and I'm trying to figure out exactly what I have.
Date code is K-24-1
Block casting is 3733950
Head casting is 3701887
Stamped ID # is 0018991F
And here's the confusion...
From what I've found, the date code suggests that this engine is from Nov of '61 but the block number lists it as an early 261 from '54. The smaller fittings for by-pass oil filtration and lack of captain's bars on the block would suggest the same.
The head is another topic all together...it's number suggests that it is from the last of the low pressure 235s, yet it has the steam holes or water passages drilled into it.
Unfortunately I have yet to find anything on the number stamped behind the dizzy.
