Vac leak?
all hoses are accounted for and we replaced many worn ones when reassembling the intake. i spend enough time looking at these lines to say pretty confidently i know all are accounted for.

Exhaust leak?
well, i got one big one right now, as the downpipe basically crumbled under its own weight when removed from the head (pretty rusty). so needless to say, the trooper is loud right now. but the squeeking noise is definitely heard over the exhaust and seems to come directly from the engine bay, not under the car.

Accessories? Bad idler on A/C? If you have it.
I thought about this. in fact, the only other thing i had in my list to try was starting the truck with all belts removed to rule out any possible problems with accessories. i'll probably do that tonight. yes, we do have a/c.

Loose nut behind the wheel? <img src="/forums/images/graemlins/smile.gif" alt="" />
you just couldn't resist, could you! I'm sure once this is all figured out, it will once again be something incrediably simple that will give you more ammo against me! <img src="/forums/images/graemlins/cheers.gif" alt="" />

Thanks for the advice though, <img src="/forums/images/graemlins/kewl.gif" alt="" />

-Rob