A great big thanks goes out to Bob, Ed and Jeff for the effort these gentlemen put in on a solution to my tach condition.  I ordered the tach from UMA today, which is part number 19-51A-201, which is a 7,000 rpm tach, 2 1/4" dia., which will operate on the 5v signal to one LS-1 coil.  Price is $141.00.  Phone number for UMA is 1-800/842-5578, in case anyone is looking for an analog tach in 2 1/4 or 3 1/8th" size.  Another plus for UMA, it is made in Virginia, Good Ole USA.  JohnD