RE: 94 2.2 "elbow" on firewall leaking antifreeze
If it's a rubber elbow that comes out of the firewall and points straight down, then your heater core is the problem. Chevy used plastic lines to connect the heater core to the hoses. The plastic line inevitably splits at the core end and it leaks like a basket.
When you replace your heater core, the newone should come with steel lines. The lines may also be able to be rotated to help you get the new core into place. You shouldn't have any further problems with it once you replace it. If your new heater core has plastic lines, I'd recommend returning it and getting one with steel lines. They're not very expensive, either.
1993 Ford F250 Supercab 7.3L IDI N/A Diesel (247,000 mi.)
1984 Mustang 6-speed 300+ HP... for now (My resto - 146,000 mi.)
1994 Z24 Convertible (My woman's ride - 122,000 mi.)
1965 VW Beetle (My woman's resto - God knows mi.)