Connecting rod differences?

[rabbie6]

I need to change one connecting rod due to it being bent.
I see lots for sale on eBay but I am wondering if there are differences between models - ie. F, K and A models?

my K model connecting rod has S82 stamped on the side and S 51 on the lower half and a 2 printed across the two halves.
I see A model connecting rods with S 56 on the side and 1 printed across the two halves on the side with a different number on the small half (S 39?)

are they actually different dimensions? thanks

 

[dirtdigger]

The k and f are the same except the f has little stronger bolts. not 100% sure if the auto is the same but I think it is. The 2 stamped on it is the code for the size of the big end to use in the chart to select the right connecting rod bearing. Either 1, 2 or a 3 stamped on them depending on the size of the big end.