Did a compression Test today

[kcfirstbuild]

I have a 1968 chevy Lwb With a 307 that has 54,000 miles on it. I ran a compression test on it today and this is what it got.

1. 130 2. 140
3. 135 4. 150
5. 135 6. 140
7. 130 8. 140

They all started at 90 or so on the first rotation then jumped up to the numbers I posted above. One sit is lower then the other not sure if its from the battery running low or not ? Where should i go from here ? Do i need to rebuild everything or will i be ok with just gaskets and seals ?

Another question. There is a hose running from the air cleaner to valve cover is that the Pcv Valve ?

This is my first build so i don't know alot but i'm learning.

And i know I should change it to a 350, but its a numbers matching motor so i would like to keep it.