Replacing the three top rails DOESN'T require the front of the motor to be taken apart. Simply remove the P/S pump and bracket on the left side and the alternator/ air pump bracket on the right side. This will allow easy access to the pressed-in pins which secure the rails. As a rule of thumb, the darker brown the rails are the closer they are to ruining your day. They can be seen with the valve covers off. This job is a lot easier than it appears to be.