The man was as good as his word. The fix came today in the mail. A FREE fix. Do you know about free stuff. It is just as good as the price. I put my engine analysis machine on and watch the tach It would go up to 2000 rpm then start jumping around. And I install the fix the tach was retarded. at 2000 it was reading 1500. But it didn't started jumping till it read a little over 3000. And then it didn't jump as much. It just made the tach very sick. OK I put the free fix in the trash can. It was worth a try.
Now I jump in my parts books. Ah ha I found something that might work.
A TACH FILTER The tach filter prevents erratic gauge operation by filtering out electrical interference from hi-power ignition systems. $15.95