air flow adjuster

i talked with this guy about a mass air adjuster he had on his 5.0. said it plugs in between the meter and harness. he said it allows you to fine tune the idle if your having problems with your mods. i assume he meant stuff like cam, heads, etc. i've heard of that before but never checked into it. he liked his. would that device be worthwhile to try? does anyone know who sells them and/or what they're called? i'm slowly gathering parts for a 347. so far i'm figuring on the following mods.

190 lph fuel pump
x-pipe
flow masters
edlebrock victor jr. i hear afr is good though.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33616&item=2476142831
c6 tranny (converter undecided)
intake undecided (probly go with edlebrock permformer 5.0 rpm II)
f303 cam
msd 6al ignition
msd probillet distributor

that brings me to another question. jegs recommends a 5 speed with that cam. is that C6 gonna be alright with that?

yeah i'd seen that one on ebay while looking for a meter. Just bought it for $61.00 haven't heard any negatives bout it. hope it works good for me. i'll let u guys know how it works out.