Dr Terry,
             Thanks.  I think I've got it.  From what you are saying, the timing marks on the balancer match the timing cover NOT the crank (and obviously not the block).  So basically if I have a red timing cover I should use a red harmonic balancer.  If I have a blue timing cover I should use a blue harmonic balancer.
              Since the blue balancer has a heavier outer ring however, I would be better off putting a blue motor timing cover on my red block so that I can use a blue motor harmonic balancer on the fully counterweighted blue motor crank.

Hi, I have a 202 red motor block and a blue motor crank.  I went to buy a harmonic balancer the other day for it, but the part numbers are different.  The crank diameters, oil seal diameters, overall diameters and balancer lengths are the same, but I'm told the timing marks may be different.  If so, are the keyways in the cranks different?  Or are the timing marks on the blocks different?  

Which Harmonic Balancer do I use?  Blue to suit the crank or red to suit the block?

Hi Ken,
      There is no bigger number AFTER the H109 etc...  These numbers I have given are the rear-most numbers and are situated on top of the head, next to the side of the rocker cover, at the rear passenger side of the head, just REARWARD of the rear water outlet boss.  The H109, D169 & C162 numbers are the closest numbers to the rear water outlet boss.

       There is however a bigger number BEFORE the H109.  It is '7412611'.  It is also located on the top, rear, passenger side of the head, near the side of the rocker cover, but is FORWARD of the rear water outlet boss.

       This longer number (7412611) is the same on each of the heads and so I don't think this number has any significance in relation to dating the head or identifying which model it came from.

Thanks Ken, but I don't quite understand.  I have three blocks and three heads.  Can you decipher this for me please?

The first is a J Block (I believe an EJ block) with a single outlet head on it.  The numbers on the head are slightly damaged but this one appears to be D169 - number is situated near the rocker cover, and rear of the rear water outlet.  Also, it might be noted that there is no large boss up front where a front water outlet could be drilled and tapped.

The second is an L Block (I believe FE-FC) with a single outlet head on it but this one has a large front boss the same size as the water outlet boss at the rear however there is no water outlet in the front boss.  (The front boss looks like you could drill and tap it if desired).   Again the numbers are gouged a bit but appear to read H109.

The third is an L Block (I believe FE-FC) with a dual water outlet head on it.  Both bosses are the same large size as in the 2nd head but with this head they are both drilled and tapped as water outlets.  The number on this head appears to be C162.

So what letter/number do you think represents the year, the month, the day?  Can you tell me what model each of these heads are please?

Hi, is there anyone out there that can help me with identifying different grey motor heads.  I was told that there were several different heads, the FX to early FJ, the late FJ to FC, the FB to EK, and the EJ heads.  If anyone knows how to identify each or any of these heads please let me know.  Have they got different casting numbers/letters?  If so, what are they?