ouch that seems like soemone didnt get the head cleaned good enough or didnt clean the bl0ck good enough or didnt take the rivet out of the head gasket before he put it in...if there were swurls on the head it could cause it to leak check your compression you may be getting shitty compression do to the head gasket not sealing and white smoke? not good could be the coolent leaking into the exhaust or may just be oil from the plugs but that normaly goes away fairly quickly keep an eye on your coolant level you may have bent a valve and its causing the bogging...im just shooting here im not completly sure without seeing the car if someone thinks im wrong in any way feel free to jump in