Troubling noise.....oh oh?

[Tiamat-red]

Ok, so recently I've had a worrysome loud "clicking" noise coming from the engine locale. Only happens while under throttle. Every gear, even overdrive. Sounds like a rattling heatshield but I'm guessing it's not. It's higher "pitched". Sounds almost like a relay firing...alot. The tranny fluid was a bit low, but that was after I changed the aftermarket filter. Refilled it and it's still there. Diff fluid is ok(full).
I can't get it to do it while in park with my head under the hood.
I do have LAN's stage 1 ecu. That would still see knock right?
Might it be an injector? Or something else fun? Broken honeycomb in the cat(s)?
I'm going to change the diff fluid(why not), and see what that looks like.
Also hook my A/F gauge back up.
But does anyone know where to look for a noise that happens under throttle?
Definately not CV joint. I know what those sound like....replaced both fronts already. It's not a grinding, more like a relay.
Other than the noise there are no driving symptoms.
Seems to be worse while going uphill, but that might just be because I'm under throttle more then.

Weird thing is it started to happen a couple of weeks after regreasing my poly swaybar bushings. Anything near there I could have broken?

Give me some places to check or I will just drive it until something falls off. That way I will know for sure.

92 LS-L AWD
Tranny filter/cooler
Stage 1 ecu
Everything else pretty much stock/rusty

[Tiamat-red]

Also, the timing belt has probably never been changed. Could that do it?