[GT289]

Most likely a replacement spring set for a long-ago cylinder head refresh. Only hipo heads had inner dampers in the factory sense.
The dual springs are HD in that they beneficially change the spring harmonics AND provide increased valve spring pressure.

I used to use the standard KD compressing lever and an air line connection to put air inside the cylinder. Don't know what tool you have.

If the cylinder heads are off KD tool makes a different one to do the job.....

 

[GT289]

So you don't think it would be worth it to change the springs? And my cool some cheap clamp like things from China. I can flex the metal by hand. I'm just going to buy a good tool so I don't have to worry about it.

Yeah, I wouldn't necessarily read that into what I wrote......
Don't know your game plan, so I don't know what to tell you. Personally, once I remove valve springs (unless one broke), I generally
replace all of them, do the valves, do the stem seals, etc. etc. If the heads are off the engine it's as good a time as any.
I'd probably match port them to the exhaust too......