Re: fuel line size?????
I used 1/2 inch for my hot 351 Cleveland, when using a Holley Blue pump.
I'm guessing your 460 is carby, so depending on how much HP you are making anywhere from 1/2 inch to twin 3/4 for a real HP monster.
A pair of Holley Blues, Blacks in parallel or most of the Barry Grant pumps would be up top your task. This might all be different if you are running methanol or alky etc.....
Remember, all of your fittings and line from carb right back to the pickup in the tank need to be the larger size, not just your line. The fuel line can only flow as well as any restriction will allow.