I am selling my amazing Boss 9 (521) that was built buy Kasse and his team. It has less than 500 miles on it and had an excellent dyno run at Kaase’s shop. 770hp/700lbs/trq. Just too much power for my 67 Mustang. Built new with the Billet Specialties front runner was $24, 920. Kaase can verify it was built at his shop. My loss is your gain. Asking 21,000 or make legitimate offer.