Engine Woes

Hello everyone, This is my first post, although I've been following the board for a couple of years now. Alright heres the deal....
I put a new engine in this summer, bought it from Quadratech, well my problem is that the exhaust mainfold was leaking I assumed it was cracked because the gaskets were so new on them, I figured this was not the case. I ordered a header, as a replacment for the "cracked manifold"(good excuse . Well as I figured the cracked mainfold was no big deal, I drove about 120miles on this. While I was driving my cj started to drive poorly, it started to stall, etc. Then started to burn white smoke, i pulled over and poped the hood. I noticed that coolant was bubbling out of the number 2 spark plug. I had it towed home, I feared that my head gasket popped but w/ only 10k on the engine and the jeep has never been close to overheating I didn't think this so. I took the mainfolds off and come to find out that exhaust manifold wasn't cracked but the gasket was infact ripped. Well I replaced the exhaust manifold with the header and reassebled. I also sucked all the coolant out of the #2 cylinder. It started up very rough, Now heres the problem.... 1) Alot of coolant blew out of the header 2)The exhaust leaks in the same exact spot. 3)The #2 clyinder fills up coolant 4)Obviously it runs very rough and burns white smoke.
Any ideas guys? My guess would be head gasket.. but why? Never overheated.... Also the header is leaking on the exact same spot as manifold. Now the header came with a very cheap gasket and I put it on anyways(bad mistake I think) Now could a cheap gasket cause any of these problems? Could these be concidence. Well I'm calling Quadratec on Monday when they open and see what they say. As it is still under warranty. Well any suggestions? Thanks!!!