Its a 1972 engine. Only one sold on Ebay this year, $93 new in box. Last year, several used ones went for around $65 each. The Falcon is a Fox 59 in an improved case. The exhaust stack has muffler mounting provisions and the crank centerline is on the plane of the bottom of the mounts; the original 59 had the crank 3/16 under the mounts. Also, you don't have to hog out the left mount to clear the bypass.