Block cast # 8703414 date stamp F 21 4 (June 21, 1954 I beleive).
Running engine, older than I was looking for but couldn't pass on a good running 261! Not quite sure what I'll do with it yet but It's sitting in my shop & I'm smiling!

Nice find. I know how you feel about not letting one get away. I hate to see choice inlines go where they are not appreciated. My shop runneth over.

Probably 3703414, the early 261s with the early style water pump are very desirable and getting hard to find.

Tim

That what it is, somewhere between paper & typing I messed that up. We had it running before removal, sounded nice. Need to check compression, etc., had the valve cover & rocker arms off, tops of valves & rockers arms look good.
Might try to swap in for a '58 up 261 as I don't have any 55 1st series & back rigs.

It get even better! Bought a running '59 C60 truck!! Drove it home, swaped carbs and got it running nice. So plan to get it ready to go into my '60 C10 next winter. Shouldn't be too hard to find a home for the 55 1st series (or another project!)and I'm in no great hurry to part with it.