My 78 has decided to blow the gasket between the j-pipe at the front of
the heater box and and the heater box itself. Unfortunately it has eroded
the heater box (due to salt over the winter and my lack of attending to it
right away.) The three bolts that join up the jpipe to the H.B. are pretty
well eroded away. Is there a repair kit for this? the rest of the heater
box is pretty well as new. 
Thanks,
Courtney