Hello, All,
I have a problem that may not be solvable, but if it can, it will be in this forum, I'm sure. I purchased a 1993 Mustang with 5.0 and five speed. I know little about the engine and neither did the PO. The engine runs okay but in attempting to determine a little about it's condition, I have run into a snag. I tried to do a routine tune-up by changing plugs, wires, cap and rotor. I ordered the standard replacement items for the tune-up. The recommended plugs would not fit the heads. There was a small shoulder above the threads on the plug that kept it from going down into the hole far enough for the plug to engage the threads. I then dug out one of the old plugs and cross referenced the number on the old plug and a totally different plug was the result. The new plug had the shoulder and the old plug did not. I exchanged the plugs for the correct ones and all was well. Now, my question is, what is the story behind these OEM plugs not fitting the head? Is there some way that I can determine if these heads are aftermarket and, if so, what should I look for? Any guidance would be appreciated.
I have a problem that may not be solvable, but if it can, it will be in this forum, I'm sure. I purchased a 1993 Mustang with 5.0 and five speed. I know little about the engine and neither did the PO. The engine runs okay but in attempting to determine a little about it's condition, I have run into a snag. I tried to do a routine tune-up by changing plugs, wires, cap and rotor. I ordered the standard replacement items for the tune-up. The recommended plugs would not fit the heads. There was a small shoulder above the threads on the plug that kept it from going down into the hole far enough for the plug to engage the threads. I then dug out one of the old plugs and cross referenced the number on the old plug and a totally different plug was the result. The new plug had the shoulder and the old plug did not. I exchanged the plugs for the correct ones and all was well. Now, my question is, what is the story behind these OEM plugs not fitting the head? Is there some way that I can determine if these heads are aftermarket and, if so, what should I look for? Any guidance would be appreciated.