GPZ1100A1 1983 chain drive piston rings

I need some clarification please, I have a GPZ1100A1 (chain drive, bucket head) motor. The bore is standard 72.5mm as are the new high top pistons (the previous were 1250 oversize but the bore was damaged).

I bought some non OEM rings off fleeby for KZ1100 81-83. The part number is 13008-5037, they fit well and appear to be ok.

A performance guy said that the rings are not correct and should be 13008-5055.

Apparently a gentleman somewhere in this forum was re-ringing his 83 A1 and compared the -5037 rings to has previous set and claims they were exactly the same.

My Question is, is the forum person correct, both sets are the same (not the first time Kawasaki did this).

If they are non oem why do they have a 'factory part number'?
If dimensions are within spec does it matter?
If it meets or exceeds the original part does it matter?


.

Makes sense, thankyou for your input. It seems there are some nippon (non OEM standard  rings with that part number), their quality looks / feels good in bore. I was just curious as to why Kawasaki has two different OEM part numbers for rings that do the same ?

Rest easy...
I recently refreshed the top end of my Lawson "Tribute" using those NIPPON rings.

 

I really liked the green / red colored oil-ring expander tips, which help ensure propper installation.

 

H.

I bought a set of these, Quality looks as good as OEM