Spark plug question

[1998Explodasport]

I recently finished my SOHC mustang motor swap a few months back and I put about 7k miles on it and when installed the motor only had 11k. I figured with such a low mileage motor I wlould leave the spark plugs in that came with the Mustang motor. Ever since I got it running it had a slight rough idle which seems to be getting a little worse. I just checked and my 2001 Explorer calls for different plugs than the 2008 Mustang motor I put in. Would this honestly cause my rough idle and poor gas mileage?? Just to let everyone know there are no engine lights and everything else on this motor is new, wires, coil pack, cam and crank sensors etc...

 

[wood1]

highly unlikely

 

[jlsparky7]

If you did a motor swap there is a lot of things that could cause a rough idle. Id start cheap and work your way up. Check wiring, grounds, fresh tank of fuel, seafoam and plugs would be a good start.