Gas leak Holley 1850

Hi guys,

been a while I came here ... but did not touch the car for a while also ...

anyway the car has been stting in my garage for almost a year without being started. I just changed the intake, reinstalled the carb and tryed it.
Surprise !!! gas was spraying from the tube connecting the two fuel bowls. I retighted the bowls 4 bolts, same result.

Removed the carb, removed the bowls, and saw that the o-ring were kind of dry. I have redone the carb, about two years ago, with a gasket kit that I got at Stowe flea market.

Turns out that o-ring, good for gas, are unavailable around here.
I tought I could put back the tube and the bowls, and pack the opeingin around the tube with black RTV. Anyone ever used black RTV for something like that?