Rozema

I had a motor swap done on my 96 v6. The engine is a 98. I have a misfire and have been replacing all kinds of parts to solve the issue. Still nothing has solved it. New plugs wires, o2 sensors on bank two. New EGR. Fuel injector cleaner. High quality gas. Cam shaft sensor replaced. Have an exhaust leak, could this cause it? It's felt only at idle. Feels like a hick up. No coolant in oil or white smoke. Also had thermostat changed about a moth ago. Before that I was loosing coolant in the overflow tank. But radiator level seemed to be fine. After thermostat changed still loosing coolant but not in overflow but it's the radiator side now. Any suggestions??? First mustang ive owned and put so much money and time into. All a learning process, but wouldn't give her up for anything just want my pony running top notch. All advice would be greatly appreciated. Also I've been looking for spots for the coolant leak and see nothing on the ground. Upper and lower hoses been replaced not swallow. Again thank you for all suggestions.