When performing the ultimate tbi mod for the injector spacer and you have to modify the tbi all you have to do is grind down the back edge/ridges (the rim of the tbi). Right? You just have to grind it even/flat. Just making sure that i dont screw anything up.

 

I just got through doing mine a while ago. while your at it take it down flush and, don't leave any metal sticking up. You shouldn't be able to feel any sort of rigde when your done. It should be a nice smooth curl int othe bores. I did mine all the was around. You might want to decide not to do the back towards the injector pod tower. It's kind of a waste of time, since it's in the way.
hope I was a help.

Andy