Well as you said the job was easy - not 10.5 hours, but more like 1.5. Anyway in your previous email you indicated if the core was leaking it should have been on the floorboard. After removing the core, your email started to register since the construction of core should have been straight down rather than the drain tube (a/c condensation?). The green fluid (assumed to be anti-freeze) was coming out the drain tube is now my guess, dye from air condition recharge last year. I wound up putting the original heating core back in and am still stumped about the mystery fluid.

Thanks for the advice.