[Mr70]

I understand what your saying Verne,but actually this part# shows up as a 1965 model application Only,used on the PASSENGER cars & has bosses for heat tube..Not used in 1966 as I stated earlier.
In 1966 the RH Manifold had a different number,Part#3884504,and loss the heat tube bosses.
So I guess if this Manifold didn't find it's way onto a late build engine originally,it was really a service part.