Good news: T-350 is common, strong, available, fixable. Bad news: it is almost impossible to feed a one-piece fuel line from the motor to the fuel tank with the body on the frame- and that's how the factory did it. Better news: I ran brand new fuel line by NOT routing it exactly like the factory did. I just went around the obvious impossible road blocks and I used five foot double flared sections connected with proper unions. I know- double flaring is for brake lines. True. So I'm a belt-and-braces kind of guy. Since fuel supply line operates under suction you can get away with straight cut lines connected with compression fittings. The return line is very low pressure too. Either way works.
Maybe I'm ignorant, but I'm pretty sure my fuel line is pressurized and not under vacuum since the fuel pump is in the back