Since the first inline six cylinder Chevrolet engines were introduced in 1929, they had been attached to the front cross member of the car and truck frame. There were no actual rear engine mounts. The engine was secured to the bellhousing at the rear which was attached to the frame rails.
For the Chevrolet “car only” this changed in 1952. A side mounting system was on the car however, the truck continued with the front mounting system. Beginning in 1952 three threaded holes were then placed on each side of all 216 cubic inch engines to secure the new mount. To keep it simple, trucks used this same engine block but no side mounts were attached. Therefore, the last two years of the truck 216 engine has three unused side mount holes on each side of the block.
Resulting Fuel Pump Changes: The new side mounts created a change in the car fuel pump construction. The car fuel lines could no longer run parallel to the engine block as the year before and on trucks. The new side mount became an obstacle. The fuel line to and from the fuel pump had to be modified to run around the newly introduced side mount!
To save money, GM was able to continue with the same fuel pump by removing the six fasteners that connect the top and bottom halves, twist the top one bolt position, and re-secure the evenly spaced fasteners. An easy fix!
Part’s Store Error: Some aftermarket part books list the 1952-53 Chevrolet fuel pumps with a different part number than the 1951 and earlier but, this is only partly correct. The trucks still required the earlier pump as they have no side mounts and should carry the older part number.
Imagine the owner of a 1952-53 truck who needs a fuel pump. He is sold a car unit at his local parts store (because they show only one part number.) The pump mounts to the block perfectly but his fuel lines with not connect. He does not realize he can remove the six bolts and reposition the top half. Even if he realizes this might fix the problem, he will not change it for fear of voiding any pump warrantee. The store counter man has no idea! Too bad for the 1952-53 truck owner! He will now need to buy different fuel lines and bend them to fit the incorrect fuel pump.
The source that wrote the fuel pump catalog had no idea. This can be a big problem for the owners of 1952-53 Chevy truck. The do it yourself mechanic then buys store brand straight fuel lines, bends them to fit and flairs the ends like the originals. Yes, he is back on the road but with ugly home-made fuel lines and lots of extra money spent.