I have a ranchero with a 74 big block 460 out of a truck, how would i fabricate trans coolant lines?

Measure distance between trans fitting and radiator and size of line. If you have old fittings can use on new lines. You can buy flexible steel tubing at auto parts store, If not sold by the foot you'll have to buy more than one to make up distance add about 3ft extra for each for any bends. If fittings are different size at trans and rad they have step down fittings. You will need a pipe cutter and a flange making tool. Hope that's enough info.