Without trying to sound like a smart azz and at the risk of repeating myself, have you've confirmed that the motor is making the 530 hp that it should now? The car should go sideways from a 40 mph roll in second gear, and run a high 11 et at probably 118 mph in full street trim. If you don't confirm where you are at, I'm afraid that you are spending good money after bad. Its about way more than the sum of the parts, and your parts are not that far off, IMO.

Secondly, now that we know your cylinder pressure is good, I don't think the 84 cc heads will help, again, IMO

Third, with that XEHL cam there is a good chance that the lifters are about done at 5500 anyways. So I suspect that the actual improvement from an intake swap will not be fully realized, and certainly not enough to "feel" a lot better. Again, IMO

Finally, if everything is perfect now and it runs as it should and does not meet your expectations, then to make a meaningful change will take a lot more than the heads you purchased and intake, again, IMO.