what mods would i have to do to a 1950 Chevy 3100 to drive 1000+miles in a day?

Well if you are going to drive the full 24 hours you only have to average about 42 mph.

Anything that has been sitting for 30 years is going to need every piece of rubber replaced. This would be tires, radiator hoses, heater hoses, vacuum hoses, fuel hoses, brake hoses, fuel pump, and likely a carb kit. You will also want to change all the fluids. This would be engine oil, transmission oil, brake fluid, and coolant. What ever is in the fuel tank will likely have to be flushed out. If you are lucky after all that it will run.

to tell you the truth man, i would look into either rebuilding it bumper to bumper or just look for a newer car

Tires, complete brake job, major tune up, all hoses and belts,repack all bearings, fix all lights, complete service. about $3000 should cover that. And seeing about 50 is top speed, that should take you the full 24 hours including stops for gas and food. Good Luck.