14 sec. windstar

ok so i had my swap in for a couple monthes... it ran a 13.6... its a fully built b16a ina 90 da... but ya heres my problem i was redoing my exuast a couple days ago and i was at a buddys house well i did new headers and i cut and rewelded the bracket on the connecting peice of my header.... so my buddy goes to bed and i was hooking up the rest of my pipping and the bracket so just a lil off and i couldnt get it to bolt up so i drive it back to my house open header (block away) and tommorrow i drive it back over there and reconneted the pipping... and when i started it up it was mis firing when i would floor it but not when idleing of half floored so i was checking my dizzy and then i started pulling plug wires out cyl.#4 once i pulled out the plug wire had standing coolant in it... first thought head gasket... later now tht im thinking about it... its probally a cracked head...hoping not tho what do you guys think? im pulling the head off right now to check but its really getting to me more i think about it