Compression testers can be found at a local auto parts store, Sears, or even at a Walmart. I recommend getting a decent one though so you can actually trust it, so Walmart is not the best choice just a last resort.
I had to file the lip off of my 35mm so that it would fit into the airbox adapter (billet with an o-ring). I wouldn't have had to do that if I'd have went with a K&N setup without the airbox. Not sure why you'd have to do it with a Blaster though??? I'm sure rocketpig will take care of ya.
The more I think about it I have some additions to my tying him out in the desert with a cut open nut sack. I think they should prop his head up so he can see his balls and also give him a feeding tube to keep him alive while the lizards and bugs and other critters can come up and start chewing on his sack and then start working their way up the rest of him.