I looks like you do not have an original intake manifold. Can you post a link to a picture?

B 61 848/850 does not designate anything helpful.

You have a 56-63 235 head: 3836848

The block date code is for 1962: D 24 2

What is the engine ID serial number?
http://www.1954advance-design.com/Web%20images/casting-code-photos/codes-ser-nums.html