What is your:
1. Engine Serial Number
2. Head casting code
3. Head casting date
4. Block casting code
5. Block casting date
Here are locations for those codes. Engine blocks and heads were cast after the 261 was last standard equipment/option in 1963.
When you say 1/2" tubing was used, were both the "full flow" fittings into the block 1/2" NPT?
