ok...so after pming Bonneville94V688, he confirmed what i did is very likely the reason for the violent backfire. ok. so i'm toast. thanks for the help team.
popatim, as for your question:
could a damaged MAP or BAP cause this too?
um...maybe, but in my case, i def. blew either a gasket or the manifold itself. we now know that for sure. thanks to my stupidity. thanks for your suggestions though.
now, if everyone will excuse me, i am going to bang my head on the wall for a few hours, and readmit myself to Bill and Bob'* asylum.