Yes, that is possible, but a typical 8th would have a substitute standard stock with a large-diameter round recoil lug bolt, no grasping grooves, and most often the "Type 99" script has been eliminated, though there are exceptions to that.
It's also possible it's a 9th series Izawa with a light or mis-stamped nagoya sub-arsenal mark. Izawa 9th series rifles are often found with welded fixed sights but earlier pattern 2 piece stocks like yours.
Finally, it could be an early 8th series with a replacement stock.