Don't get ahead of yourself. Do a diagnostic of the engine and see whats going on.
Any smoke?
2 or 4 bbl?
What are the head #s? (under valvecover)
What is the block casting #? (driver's side of bellhousing behind cyl head.)
Do a compression test.
The engine may just be badly out of tune. You can also take that PG out and swap in a TH-350 very easily.
Preaching the Hot Rod Gospel according to the 4-stroke apostles:
Suck, Squish, Fire and Fumes
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