90 CRX DX. I finished getting the new rebuilt head on my Rex and was putting in the spark plugs. One plug went in easy. Two were difficult and one wont quite make it all the way. Question: Could i run a tap down these holes and what size tap would i need? Anyone ever had this problem? Thanks. This is the only thing keeping from starting the engine.

 

i have done it on a chevy motor, but make sure to put some grease on the tap to try to catch as many shavings as possible and then use a big shop vac to get whatever you couldnt trap out of the motor....