To start off with, I don’t buy into the idea that light weight pulleys are going to add any meaningful HP, ok maybe you see 1whp but that’s well within the margin for error of a dyno. I don’t want to underdrive anything here, that can have some nasty side effects.

I did some searching, and I didn’t see any comments as to the effect they have as far as compensating for the drag on the engine from the A/C (when on) or the effect they would have on the idle (again, the drag on the engine).

You’ve got a lot of components at and just off idle that drag on the engine, so it would be nice to get that “no A/C” launch feel from a stop that you miss when the A/C is turned on.

While were on the subject, how about the lighter flywheel? Do people notice the car idling higher as far as RPM?

I’d like to take as much drag off the engine as possible for a variety of reasons, anything hanging and spinning on the car should be as light as possible right?

i have the act prolight flywheel and i noticed the rpm is similar to stock on idle. the only thing i noticed is that the car idles a little rougher than before. but acceleration has been slightly improved in 1st and 2nd gear.

Have act prolight + AP pulley . Idle is fine no difference I can detect .
A/C does not seem to add drag from idle , then again I didn't notice it before either .
Really - I don't think you are going to notice a difference apart from the flywheel requireing a few extra revs to get you underway.
I really would like to jump back in a stock 8 & see what the differences are .
I can tell you that my 8 now feels like it has more torque low down as well as hp up top compared to how it used to feel pre mods.

PS : The 20% uderdrive has not compromised A/C,Alternator or water pump as far as I can tell .

MS flywheel and AP pulley, only major difference is quicker rev, and they drop faster when shifting. Slightly better pull in 1st and second. No idea since its been brick out here.