I went to the junkyard today and found a 1968 Impala 4dr. It had a 307 in it (from what the emblems said may not be the original engine) and the heads on it were in great shape. They were complete, they inlcuded rocker arms, valve springs, etc. The casting number is 3927185 and they check out to have came off of a 307/327/350 and have a 70cc chamber. Please if you have any additional info tell me? Also how good would these heads be on a 350 that may be used for racing(approx 400 HP) Do you think these heads are worth $60?