I finally found a machine shop that will rebore my N8 throttle body, w/no problem. Shop has been doing custom throttle body work for nines years out in California.
http://www.rvmorsemachine.com/pages/1/index.htm
He has assured me he has never had a PCM problem with any GM cable driven TB and I'm going to send him mine. Seems real straightforward and seems to now TB'*. Even told me not to buy a powerplate spacer from him stating my plenum is already more than adequate and they found no improvement in port style injection.
He is going to CNC me a spacer plate with nitrous jet hole drilled and tapped, saving me from drilling TB body. $125.The rebore includes: boring, custom fit CAD designed throttle blades, reducing shaft profile, installing button head screws, milling topside and tumble polishing $227 & $8.95 Shipping. I not endorsing him yet but will post pics when I get it back and details when She'* back together. dizzyJohn

The name Frankenbonne is already taken.

I've done some of those TB modifications personally. As long as your MAF sensor can adapt and range the new flow, you'll be fine. Reducing the shaft profile will generally only gain you a couple percent at the top end, but I do it anyway while I'm in there. Flat head screws (countersunk) would have a lower side profile than the button heads. I'd bet there'* enough room to do that.

Thanks for your input Will and I'll mention the recessed screws as we are still discussing things. And I didnt know some else named their car that or maybe I read and then it stuck in my head...Cars starting to look like frankenstien 'cept aint together or stiched up yet. I'm pulling a "Mortehl" and have to many ideas going at the same time. Cant find anyone around here who will touch the super wide headlight and clear yet but still looking.