340 heads??

Nothing about the casting numbers will make them a TA head. The only way to identify them as a TA head is the offset intake pushrod holes. It's VERY obvious. If it hasn't jumped out at you as stange looking, I doubt they are TA heads. I've had a couple of sets of 2.02" standard 340 "O" heads. All of the TA heads I have seen have been J castings, but I'm not saying that they all are.