K3 cylinder head

Hi all
I have a now redundant front head for my K3 and I'm searching for a replacement, what I'd like to know is about the code stamped just above the exhaust port, my guess is some kind of model or part number S - 3 17G. Now other sv's heads on ebay seem to have S - 4 17G etc....
I really would appreciate some help working out what I can or can't use.

I don't need to know the whole single/twin spark gumpf, I know about that. I just want to be sure I get a head for a pointy like mine hence the curiosity about the code.

Many thanks

I have one for sale, but I take it you don't want it?

Hi mate, I've still got you in mind. I just want to be sure I get everything absolutely right before I commit to buying anything as I'm trying to undo the mess of the cylinder head on as tight a budget as possible so making sure I do all my research.

Has the head you've got for sale got good internals (valves etc) and more importantly good condition stud holes for the exhaust.
The barrel I've checked out and I think I can get away without needing.... replacement head however is a definite

Many thanks