okay, some of you may know my car does not idle very well. its like its constantly searching for the correct rpm, yet it never gets there. The car will automatically rev it self up above 1000 rpms then slowly let its self down to around 800 were it starts to run rough again,you can feel this roughness inside the car. It does this cold or even when its warmed up, about 95 % of the time. There is no stored codes on the car for this. And the whole tune up thing has been done (msd wires, coils, and Delco plugs).
Ive ruled out all the filters, as i have changed them as well.
how interchangeable are these IAC valves, could i take on from a junkyard 87 Bonnie LE ?

An IAC valve wouldn't be a good wrecker part. The longer they sit, the worse they get. It'll be all gummed up and nasty. Have you considered removing yours and cleaning it first? Is there an 8-digit part number on yours?

i will have to check that Bill, possibly in shop class next week when i have car back from my grandparents place. Are they a cheap item to replace...im gunna check GMPD for it.