426 Hemi Exhaust Manifolds Date Code Help? NOW PICTURES

In the stash of hemi engines and parts that i purchased, were 3 sets of hemi exhaust manifolds.
I need to figure out which ones belong to one another as matched pairs.
I'm pretty sure i can figure out one pair that belong together, but the other ones i don't know how to brake down the number and letter codes.
Any of you Mopar guru's out there on Moparts know how to do it?
Anyway, here are the codes on the LT. side manifolds.
A 7 6
7 J A
7 M A
RT. side manifolds
4 5 6
3 A B
1 5 G or maybe 1 5 6 can't really tell.
I'm sure some die hard hemi guru out there can tell. Care to send me to hemi exhaust manifold college this afternoon.
Thank's for the help. Jim V.

Before i go and e Bay these things, i still need some help in identifing which ones belong to one another as matched pairs.
Anyone?????

For the Monday morning crowd.
Where have all the experts gone, when you need them?
Anyone?

http://www.mymopar.com/extcastnumb.htm BTW, In todays world I would find a new place to store that stuff and show and tell nobody. Loose lips can sink ships.

That mymopar.com web site doesn't help me out at all.
I know what CASTING numbers are for on hemi exhaust manifolds, i want to know how to break down the codes to tell me what the Date codes on them are.
Thank,s anyway.

looks like all 66-67 manifolds some had the month letter than last digit of year,some had letter for year. just like the ealy 70 manifolds had only letters for first run than they went to ## for years

One last time.