Hey just some less sophisticated out-o-tha-box offerings, which may be entirely unrelated but still worthwhile checks regarding a new build:
-First off I'm sure you've gotten another set of eyes under the hood to catch anything obvious.
-If using stock ex manifolds then confirmed they don't have the famous hidden crack under the heat shield.
-Weak or wonky O2s? Again, have no idea whether involved but wonder if implicated as cascading factor(s).
-Wonky FPR or pump which manifests itself only at higher revs?
-A smoke machine sounds professional for checking leaks, but never seen one used. Have you ruled out ether or throttle body cleaner for maybe better test?
-A whole 'nother ECU PCM would quickly eliminate that from the mix if you have one or more spare ones.
Sure interested in what it ends up. GL
\'96SS SOB: SSRI, Herter Tune, Tri-Y II, SLP SS, 3000 Edge, F/HO bars, METCO extendeds and CV MMC, Bilsteins, currently Vredestein Ultrac Sessanta (315/35 rear)
\'96FWB BUW-Butt Ugly White: SS Bars, METCO LCAs, Koni Reds, PowerTrax No-Slip