Engine blowing oil hesitating. Only low RPM!

Hello. Im Jeff Miller from buffalo NY. I hope I got the right email to ask this. I hope I get a reply or some help. I have a 2001 mustang GT 4.6 SOHC vin x. I have no idea what the hell is going on with this engine. I originally had a stock engine. I went and purchased stage 2 patriot heads with comp cams the energy 2s. I called comp asking if there was any special timing. They said no just line the chains up to factory spec. So I did. Started the car and well disaster. Took it to a local mustang shop they said block and all that was trashed and I hit some valves. So I take heads to get new valves and check. Was told heads were good. Then I emailed another shop and was told those cams needed cut pistons or they would not work. Which I didn't know. So my failure. So I get a used engine which ive seen run in the car it came out of. Put the patriot heads on it. Stock cams. Stock everything else on engine. Flywheel and clutch aftermarket but doubt its an issue. I start the car. It idles amazing. Then it gets stumbly hesitant and blowing oil out tail pipes. Check spark plugs. All dry. Cylinder 1 has a touch of oil on plug. But then look down spark pkug hole into cylinders. They all have oil! From what! The heads are practically new and it's all new gaskets. And the old shortblock ran fine in its other car. Im lost. Out. A lot of time and money. Any input would be greatly appreciated. Thanks!