Could it be anything besides the OPTI?
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The RPM needle and engine struggles at about 4800 RPM and above, feels like its misfiring. 160k miles on the original vented opti. I think i'm gonna replace it with a new gmhp unit but before I do that is there any other cause?
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Looks pretty clean for an optispark how many miles? I think if I go through the effort of tearing it down, its going to get a new one. Its unfortunate that the screws backed off, heard of using locktite to fix it. Although I took it to redline like 6 times consecutively and its doing it less, but i'm not sure whats going on.
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UPDATE: The problem was the fuel pump I was losing 10psi at WOT near redline. I just finished the trap door modification. I put a Walbro Fuel Pump in (255LPH) from TRE Performance only $99. The harness was plug and play. The pump fit perfectly in the LT1 fuel pump bucket with the provided sock. I bought a 10" flex hose from autoperformanceengineering along with the foam that goes around the pump body to prevent rattling. I zip tied the bucket lid with nylon zip ties instead of glueing it. Fuel pressure stays at a constant 43 psi at WOT all the way to redline, no hesitation or misfires. The car runs like new and has a general increase in power across the board. I am very satisfied with the repair, and glad it wasn't the optispark.