Got a leak i cant find

[HvyChevy454]

got a leak somewhere from under the dash on the passenger side.i originally thought it was the antenna but i fixed that and her is still a leak it looks like it might be from the rubber around the windsheild b/c the dash will be wet and sometimes around a hard right turn my feet will get wet. it also appears that where the metal in the front of the cab it pressed together then spot welded it lloks liek there is an epxpandable foam sealer and that will have water on it. i know ther is no rust anywhere in that area b/c i had it apart. has anybody else had a problem like this?