1968 Catalina carb/fuel system nightmares!! help!!

my friend's 1968 Pontiac Catalina is having hella carburetor/fuel system issues. he just had the carb rebiult professionally, and it seemed fine for about a week or two then started leaking gas in steady drops right by where the fuel filter and main fuel line is, just like what was one of the symptoms before the carb was rebuilt (there were other symptoms). he noticed this yesterday on the way home from work. a few months ago, there was a new carb that was bought but it was acting funny so he took it back and put this one back on. it should be noted that this is not the original carb, it is one off a 1974 chevy. this was done before he got the car from a deceased uncle. the seals were all replaced when the carb was just rebuilt so it is not like they are rotted or anything. and they were tightened down as tight as possible, as well as the carb itself. and, yes the carb was put on the right way (screws even, etc). there are no holes in the fuel line itself at all. it stopped leaking when it was stopped and cooled off, but then when he started it back up and ran it again, it started leaking even worse. him and i love this car but are getting really sick of having to f*** with it, not knowing what is going on.

what could be the problem??? thanx for all help

Welcome to AF!!

It sounds like you have a problem with the threads on the carb. in that they are either warn or the housing inside is cracked and allowing fuel to leak out. It is possible that the housing was cracked by overtightening the connection. You can try some thread sealant or teflon tape on this connection. The reason I say this is because the leak only occurs when the carb and engine are hot. I would not run this carb and would look for another one. Although they are expensive you may end up burning the entire car up for the cost of a carb.