I bought a Gen 3 head, with advertised HKS 272 and 264 cams, but after dismantling I notice there is no indication of HKS.
Internet searches, some say hks should be stamped on there, others say hks dont stamp.
I worked out the valve cover is actually a gen 3 3SGE, so maybe I got done and these are 3SGE cams?
If anyone could shed some light that would be great

If it helps, my gen 2 272 cams had hks stamped on them

Never seen any HKS cams without the HKS stamped on them in my experience.

That said, ive never seen toyota cams without some part number cast into them. Does it have that at all?

No number stamped on the end of them (the side furthest from the cam gears).
 
Every set of HKS cam I've seen for 4AG's have the duration stamped that way.
 
Otherwise buy a set of vernier calipers and measure the lift yourself.

I never recalled seeing HKS on mine so just had a look at it is in there

Maybe depends on when it was produced. They've been sold over many years.