[paulspickupparts]

Looking at the location of of your frame mounts for you radiator support you do have the 6 cylinder mounts and not the V8 support mounts . That is a good thing as your radiator is fitting forward as far as you can go. One way to tell which you have is to look at your frame vin number near where the steering box mounts . If it has a V in the first few digits it it is and original V-8 frame . If it is a 6 cylinder frame it will not have the V in the first few digits .

Looking at your photos of thickness of Radiator + Shroud + Fan Cage + Fan Motor sticking out behind cage equals a fairly long distance . When you add that to your long water pump you are eating up a lot of space. I agree with Joedoh on losing the shroud which may give you the distance you need and or find a fan motor that tucks in a little closer.

Ogre has a good point but remember 58-59 frames are different as are the radiator support . I would have to double check but pretty sure the 58-59 frames are a little longer . Not the wheelbase , just the frames. Hopefully your engine is in the right place . Sometimes aftermarket companies make a one size fits all. The 55-57 frames vary from the 58-59 frames . Sometimes it ok , sometimes its not.

NeoJuice might have the best and easiest solution . Lots of guys run pushers