IF Stripper clips are a magazine which could, and probably WOULD be argued, you still have to buy it first, before you can grind off the bayonet lug... and as it can accept the 8 round stripper clips, you're stuck in a chicken or the egg contest you can't easily win.
"Tin foil hat off time"....
Let's use some of our "at least third grade critical thinking skills":
You buy a Garand.
It does not COME with clips.
Change out the gas cylinder.
Go buy 5 round clips.
Lock and Load.
And if it comes down to this being an issue, methinks the CMP will be smart enough to sell modified gas cylinders ab-initio to buyers in NY. My guess is that it will not be an issue.