Beacon,
Your first post stated the 3835499 code is on the block - is it?
The engine serial number preface, JEA is for a 1951 235.
If you found the 3835499 casting code on the head, and that is a 261 head bolted to a 1951 block, it would be interesting to know how many head bolts are there (15 bolts in 51 and 18 bolts in 54).
Tim