I installed an aftermarket aluminum radiator in my '72 Challenger because upping the hp means more heat. The overflow pipe is a press fit into the side of the neck that the radiator cap goes on to. The problem is the overflow pipe is a bit loose. I don't think it'll properly "suck" coolant back from the overflow tank, it'll just suck air.
Is there a right angle swaging tool or something I can use to stick in the top of the radiator and try to expand the tube a bit so it fits snugly? All the pieces are aluminum.
I tried smearing it with gasket sealer, but I don't think that'll work reliably.