Kim, these pics should help. there are Ebay auctions I just searched for.
Now, look closely at the underside pics in each auction. First off, again, the Groove goes on the underside of the plate edge that is lower in the bore, closer to the intake manifold opening. You will want to check the thickness of the bore wall the Groove will be cut into.
Take the Large bit, and anything with a flat straight edge. Hold the bit so the taper just behind the cutter is even with the edge of the straightedge. Now look how far below the straightedge the cutter extends down,that is how deep your Groove will be. Compare that distance to thickness of the bore wall, where the Groove will go. Now you can tell if the cutter is likely to cut through the aluminum when you Groove it. If it looks like it might break through anyplace, then build up metal epoxy on the outside surface to give added thickness, BEFORE Grooving.
This is a DBW TB, so there should be no Idle Air Control (IAC) to modify.
Use a new TB mounting gasket, installed dry--do not use silicone RTV as a sealer, gasoline dissolves RTV!
this is a simple Groove job. DBW TB's are simpler than cable drive ones, as a rule.
Next- you will be looking closely at the black stain edge. The black stain shows where the plate is at during hot idle. You will want to position the plate, so it is just a bit more open than where the black stain edge is. Ron has taught, and I find it usually is correct--to put a business card between the plate edge and bore wall, opposite to the Groove side. Use as much paper thickness as necessary to get the plate opened maybe 2 MM past the black edge. This makes sure that the plate only crosses over the Groove, somewhat past idle RPM. You Do NOT want the Groove engaged by the plat edge at hot engine idle, or you could have excess idle RPM's and surging. IT's safer to put the Groove "too far" into the plates rotation, than to put it too close to fully closed. The black carbon stain, builds up over time from fuel and oil vapors, it's a reliable indicator of hot engine idle RPM plate position. Try not to smear the black too much as you handle the TB. You can even make a scratch mark at it's edge as a reference to it. Then, if you need to relocate that position, you can, after cleaning the TB.
so- First check TB bore casting thickness, epoxy outside if needed. Then position the plate a bit past the idle position. I advise having a small vice to hold the TB in to free both hands to steady the Dremel flex shaft. Position the TB in the vice, and re-position it as you go, to keep Grooving in as flat a plane going left to right as you go.
Ok the auctions: Rats, the website won't add the links. I will email the auctions to you Kim!
Tracy