Paul,
My 1954 3104 has a
3835590 intake manifold and it has the mounting tab for a horn. The
235 truck engine block was cast February 26, 1954. It has a
3836848 head that was cast December 22, 1959. I have not had the manifold off of the engine since I have owned it, so I don't have any measurements or other info.
I found that it was painted yellow when I stripped off the top layer of paint so it may have come from a 261 engine. According to Robert Hensel's research, 1955-1957 261 cu in engines were painted yellow. Group #3.265, part #3694163 in the 1929-1957 MPC is an intake manifold with casting
#3835590 "50-57 All 6 cyl. (exc 216, D.D., COE); 57 D.D (2 Ton)".
> 1929-1957 MPC: Group #3.265, part #3694163> 3835590 intake manifold> Yellow intake manifold> Yellow 261 engine color info- Lonnie