JB Weld might hold for a day or two, but it will never make it long term. Too much expansion and contraction. New radiators aren't that bad - Spectra makes a nice one.
SPECTRA PREMIUM / COOLING DEPOT Part # CU2171 is $141 at RockAuto
2003 F-250 XLT Crew Cab 7.3L, Chrome BigTex Grille Guard, Quad pillar - 3 ISSPRO gauges (trans, pyro, boost) and DP-Tuner F6; Roush fuel pressure / temperature / oil pressure gauges, Ford Severe Duty AIS, 31 row 6.0 transmission cooler, ScanGauge II, Marinco mod, Walker BTM