I decided to not remove mine. They do help significantly with cool down between passes along with running intercooler pump of course. I was running a lightweight battery before and couldn't do this.
I haven't noticed a difference at all running mine at the track (1/4) so I don't even bother turning them on anymore. I have twin 11" Spal fans on a dual pass afco. Car is a 14' GT with VMP gen2 running 85mm pulley. I'll be removing mine soon.
Since these heads were showing up before 15's were available I think the intake mounting flange is the only difference. No one has come forward to verify CC differences in the runners or valve size differences.