Get the one's you can afford, you'll never know the difference. And anyone who tells you that he knows, is full of it. I seriously doubt anyone here has bolted on AFR's and any other competing head, back to back and could honestly tell you the difference, in either dyno numbers ( not pulled from some magazine article) and real life, seat of the pants feel.
Sorry dude, I would almost always agree with this one. But, I did try it with the butt dyno and then backed it with the track numbers.
My edelbrock RPM's were decked .035 for compression and I did a slight casting clean up and bowl rounding on them. So even there they had an advantage out of the box. They were awesome heads, and I have no complaints. But there AFR are that damned good!! I did gasket match them to the intake(edelbrocks are done from the factory), and get rid of the CNC marks and really polished the chambers for nitrous.
I knew the difference on the first drive I took. I brought the car up to 3k and floored it. The tires came loose and didn't hook til the middle of third. Nothing had changed but the heads.
At the track I didn't have 12sec67 275/50/15 to borrow so I use my own 255/50/16's. Mind you nothing changed but the heads. I went from a 2.07 60 ft. to a 1.89 and the 1/8 went from an 8.5 to a 8.3 and I picked up 3 mph. I did also go a rod that was 92 grams heavier a piece when I got the AFR's, but I'm sure that didn't help. The motor makes 360 ft/lbs to the rear. That's enough to make a few strokers jealous. This is why I push and push for AFR's 185 or 165. It cost me a difference of 400 dollars to sell my heads and buy the AFR's and I will never look back.