What's the issue? Should go right in. They do mount "upside down" from a small block.

Spin the engine over, maybe half or a full turn. The cam lobe might be at the highest point and trying to compress the arm while you mount it.

Yeah this is one of those love hate replacements...it's not too hard to install, but you gotta remove the alternator and coil if doing it on a stock A body
on the side of the road....

Assuming the patient is ready and the battery is not connected for safety (and maybe the wheels chocked), and the area is cleared of parts and wiring...
Catch pan under the pump. Undo the hoses and hard fuel line. Using a ratchet undo the 2 bolts retaining the old pump to the block. Use cleaner and
brush/scraper to clean the pad of grime and the old gasket. Use a tool like a ratchet extension while someone helps to roll the crank over and find out
where the pump cam lobe is at. Make sure the lobe is facing the drivers side or ground. Put a thin smear of RTV on the back of the pump to block gasket
and partially install with the lever over the top of the cam. The pump cannot be fully seated because of the lever... install one bolt finger tight then the other,
alternate as needed until the pump is seated to required torque specs (on a HIPo motor I loctite the bolts, as I have loosened the pump from lots of high rpm
use...).
Reattach the fuel lines, put all the other parts, wiring, and belts back where they were and fire it back up... the engine will run a bit on the gas in the carb bowl,
but may die if the pump hasn't drawn enough from the tank to fill the line and the bowl, so repeat cranking as necessary. (There will be more room to work if it's
a truck...LOL)
Yeah its a truck didn't need to remove many parts. Thanks

Good Luck

If I recall correctly, the pump arm goes above the cam.