GM IMO really needs a new engine block.
Pushrod V8's are pretty much done in the face of emissions standards. Its honestly impressive that theyve gotten this far. From here on in making the grade will require OHC for its added operating precision and VVT for its zero to hero optimum operating power band.
Ford has already embraced this in the modular V8's Chevy still faces the transition. that is why the 350 is gone, the only option you have is to shrink the engine to meet specs.

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it just needs more voltage