[Coupeguy2001]

Hi Dennee,
You have a long water pump.
Back in the 50's, they were the shorter version, and the truck was designed to use one with the engine in the original position.
To make your dimensions work, you might have to use one.
Summit racing and other vendors sell two groove pullies for the short pump and a matching one on the crankshaft.
You will have to get your new brackets to line up with the short version, or do away with the clutch fan, and use a thin electric fan or some sort of flex fan and keep your pump.
Another alternative is a custom radiator.
My 57 uses a 3 row aluminum one, but you might be able to get away with a 2 row. mine is over 3 inches thick, but a 2 row might just come in at 2 inches. ( each row is about 1 inch wide).
The only way you will know is to find a vendor that sells aluminum radiators and start measuring.
Although, snce we are a limited market, the vendor may not have a radiator in stock and only be able to provide pictures and dimensions.