Is this what you ordered from Summit?
http://www.summitracing.com/parts/urm-3-312/applications/make/chevrolet/year/1952

If not, what is the part number you ordered?

An electric choke was not used on any 216 carburetor.

I think that no type of automatic choke was used on any 216 truck carburetor/manifold.

Any Rochester 1-barrel carburetor with any type of automatic choke would have the wider, non-216, mounting-bolt pattern/distance.

Tim
1954Advance-Design.com
1954 3106 Carryall Suburban
1954 3104 5-window pickup w/Hydra-Matic
The 216 and early 235 engines are not "splash oilers" -- this is a splash oiler.