If you have no belt, You May need to measure the length of the Belt path... that along with the width of the pulley groove will place you in the right size... :smile:KennyV
AC stands for Allis Chalmers. Have you tries your local Simplicity dealer. Simplicity was Allis Chalmers for sometime. 1690673 was a model number the I found for an Allis Chalmers built in 1979. Do you have any engine model numbers?
