Lionel, I find the F217D as a 57-58 283 - 185Hp 2 barrel installed in cars&trucks. I doubt it has humpheads but they did have small 58 cc. chambers to help raise the compression but also the smaller valves 175. The camelhump heads are 64 cc with the larger valves 202 and 195. Is the last number on the other one actually Y3 or could it be a YZ or YS. Those show a mid 60's 327 with between 220 and 240 hp. The last 327's came out in 1969 and after that it became the 350.
my .02's
