cylinder temperature

Help refresh my memory. I have 2 cyl on my car that are runnig hotter than the rest, most are at 290 at the exhaust flange but the number 3 cyl is running like 520 and the number 6 is running 425 or so. I just got this thing put together (see sig) and have about 40 miles on it. It runs great bocoo power but I checked the temp with one of those laser temp readers just for the hell of it. Is it too much fuel or not enough fuel that causes this?? I can't remember. anyway another tid bit is that I still need to put in a fuel pump and reg and set the pressure ( no money right now). so am sure the car is a little lean right now.

found the problem

Well I never got to test the injector. As Iwas taking it for a test drive it started popping in the intake (very loud) I just pulled the passenger side valve cover and the number 3 cyl exhaust rocker stud snapped off. No damage to anything else valve looks OK and I can move it with a soft hammer. MY questoin is do You think I should pull the head or just replace the stud???? I will also double check the injector also since that cyl was running hot. I guess I heard it in the intake because the exhause gas had no where to go. That will cause the heat also I dunno just reaching for answeres to the cause.