Yes, I think you've got it. Both intake and exhaust valves on one cylinder, the one that's at TDC on the compression stroke, should have some play in them and are at the proper point for setting. Both valves on the other cylinder should be tight. Now, this is assuming the valves were set somewhat close to spec to begin with. On a new-to-you motor, they could be way off, some being very loose, some very tight. That's why you want to run through the routine that Leo outlined and watch the valves open and close as you turn the motor over by hand. That way you can determine exactly when the cylinder is at TDC on the compression stroke and ready for valve adjusting. I start with the left cylinder because it's easier to watch the valve action as I turn the motor over by hand. Once those valves are set, another complete (360°) rotation brings the other cylinder up to TDC on the compression stroke and it can have it's valves set. Yes, you want to use a wrench on the alternator nut or you'll run past the "T" mark. A ratchet is no good for this.