Since it's a non-pressurized overflow rather than a pressurized reservoir, any overflow will work. The combo tank would be a tidy upgrade.Speaking of radiators, my overflow tank has a nice crack in the top by where the hose goes in. Is there any place that sells them? Auto zone and LMC truck sell universal ones, but I was wondering if the overflow tank/ windshield wiper resivoir out of a 1994 F series would work?