New engine has loss of compression

So my 360 has about 3k miles on it now and I stared it the other day, it wasn't started for a while so it took a bit of cranking. I started listening to the starter and noticed it ever so slightly sped up as It was cranking in one spot, which from what I understand shouldn't happen, it should be even.

The motor is a .30 over 360, eddy RPM heads, comp 268 cam, weiand intake, holly carb etc, not that anything besides the pistons and heads matter really. I installed the pistons, and they were gapped properly. The car doesn't burn a drop of oil or smoke, and being so new I highly doubt that I have a ring failure. It also runs really strong (So I think anyways). But I think I know where the problem is...the eddy heads. For some stupid reason I just took them out of the box, looked them over for obvious defects and ran them...I understand that ootb they can have some issues. I just wanted to hear the damn car start, my mistake really.

So is it common for these heads to have valves that don't seal sometimes? I know my grandpa bought a car with eddy heads that the guy just threw on, and my machine shop told us that all of those heads need a valve job right away for them to perform well. And what is the best way to test, compression test, leakdown test? I have no issue taking the heads off and take them in for a valve job as the car is sitting in my garage for the winter.



[ame="http://s72.photobucket.com/user/kellyb43/media/IMG_2736_zpswb6lvosz.mp4.html?sort=3&o=0"]IMG_2736_zpswb6lvosz.mp4 Video by kellyb43 | Photobucket@@AMEPARAM@@http://i72.photobucket.com/albums/i189/kellyb43/bth_IMG_2736_zpswb6lvosz.mp4@@AMEPARAM@@72.photobucket.com/albums/i189/kellyb43/bth_IMG_2736_zpswb6lvosz.mp4[/ame]

This is what it sounds like trying to start it, it may be hard to hear but its not an even sound, hopefully it works.