According to my copy of the SCS&W 3rd Edition the pinned barrel was eliminated in 1982. Doesn't say when in 1982, so I'm quite sure there are pinned barrels out there.
There are 2 of them here: 88K and 94K. Both are pinned.
I suspect because of your xxxK serial prefix, the one you ask about may not be pinned. If I get a few minutes - will check some other similar K frames like model 66's, 64's, etc. They should be in the same serial ranges.