Guess What I Did
Requoting myself just for background:
..."I tore the old AC Delco apart, and prompting snapped 3 of the 4 Torx screws. There was no meat to get a grab to get out the pieces. I read another guy had the same happen, but he's crafty and drilled them and just used some bolts & nuts."
40 minutes with grandpa's old drill press and tiny picks, and was able to restore the threads:
Now it's just a matter of tearing out the Spectra opti (again) and moving all the original parts back into this factory unit, along with the ACDelco tuneup kit. It's my last hope of losing the P0336 code before simply getting it tuned out. Also, after removing the two bearing retainer bolts it is very lose in its race. I'll pick whatever Loc-Tite spec was decided in the 'Opti Dissection' thread to seat it.
\'96SS SOB: SSRI, Herter Tune, Tri-Y II, , 3000 Edge, F/HO bars, METCO extendeds with CV MMC, Bilsteins, currently Vredestein Ultrac Sessanta (315/35 rear)
\'96FWB BUW-Butt Ugly White: PCMPerformance tune, HomeDepot pipe w/ swissed filter, 1/2 SLP s.s. catback with H- and Flow Super 50s, oem opti rebuilt 3 times, SS Bars, METCO LCAs, Airlift 1000, Monroe SS, PowerTrax No-Slip, and now CTS wheels with +1 rubber. Finally, wait for it... LT-4 knock sensor!