i have several p.i. heads for the 429/460 but they are off of 73-74 engines. they have cobra jet valves in a std.heads.i have a set on my 69 ford which i polished the chambers and ported and polished the exhaust ports. left the intakes the same.runs great.in 69 i'm not sure that they would be any different then regular heads. when i did the machine work on these heads i had to replace a couple valves. the parts book only had 1972-1974 llisting for the valves except for 1969-1971 cobra jet which were the same part number, except harden......