Early 331-354-392 hemi mechanical stack injection. I've had these 20 years and got them from Alkydigger way back when. Everything is in great shape with no slop or binding. Bores measure 2.430 (2 7/16"). A second set of stacks are included. What you see is what I have. These are getting harder to find. Shipping costs are on the buyer, I will box these and get a quote for the upper 48 states. They are both stamped 796 and if Hilborn was still around I'd dig on the history of them a bit. I doubt Holley has kept that policy. Thanks for looking.