Throttle body gurus needed

Hello all,

My Chevy 1500 truck with a 4.3 was starting hard and running rough. So I bought a full TB repair kit and went to work disassembling and cleaning 'er up. No problems except the idle air control valve seems to be stuck halfway open? And the gasket kit came with TWO base gaskets - which do I use?
The first photo shows the IAC installed. The TB is cold and off the vehicle, with no electronics attached. See how the valve isn't extended enough to seat in the valve opening? Should it be like this when not energized or is it normal? The next photo shows the IAC valve in the position it may be stuck in? Any way to test it since it has four wire ferrules. ?Also notice the two base gaskets - one with a passageway between the barrels and one flat across. Use which? The ruined one I took off might not have had a passageway but it was all crumbled and disintegrated upon separation. Couldn't even look at the pieces to tell. Thanks in advance for any answers, advice, tips, sympathy. Tom http://i27.photobucket.com/albums/c187/highlandlake/IAC.jpg
http://i27.photobucket.com/albums/c187/highlandlake/gaskets.jpg

Ooops, forgot some details in my post: It's a 1990 4.3 with no cruise control, base model engine, automatic transmission. I put my question in this forum because the 4.3 went into more S-10's than full size Chevy's.
Thanks for your help. Tom