This isn't a lawnmover valve spring your compressing. Its a pretty beefy one. You may compress it with both hands but what are you going to use to put the keepers in? What I have found is that that the 4v compressor tool works great for the intake cams and the 2v tool would work better on the exhaust cams.........that is with the motor in the car. Either way be prepared for a lot of cussing and cuts and scrapes on your hands.
It definitely is a journey..and the fact that there are 32 of them, makes it a pain.. ESPECIALLY if you have upgraded valve springs, I felt quite a difference.
I just had the shop that did my heads also assemble the valvetrain for me, they have a special machine that makes quick work of it.