Yes that 1.70 is closed height
There is no spec for open, but pressure specs at a certain lift number
Average lift? Consider a cam with .485 lift divided by the rocker arm ratio of 1.6
Then use that number to test your springs pressure
You only measure pressure at lift and the installed height (of 1.70) is to assure you have adequate seat pressure

 

So if measured at closed 1.7", springs are 60 and 125Lbs ! Seems quite weak.

 

I would replace them all
Maybe get one new one, and test that for pressure
About 125 lbs. closed pressure comes to mind when I built my 302 back in the day

 

Eric, there are a few good videos you should watch from this guy on valve spring installed height and other engine rebuilding stuff
I watched a few and only see him contradict himself once
Myvintageiron7512 on YouTube
He has 4 or 5 videos on cylinder heads