Gen 4 5.3 Block and crank ready for rod, pistons, and cam 821 heads one dropped a valve seat Bare 799 heads Looking for an ar9 with mat9 upper or brn9 upper prefer the 5.5in for both Interested in other builds lmk what you have worse I can say is no The 821 heads alone are worth more then the mat9 upper so this is a fair offer, all for complete gun Text me 7276876897