Stall on the 904 is kinda dodgy, PTC built the converter, they said stall will be 2800-3200. There is not a lot of sources for a lockup 904 in today’s market.
Weird deal on the Dyno the engine had a strong vacuum signal on every pull.
Not married to the fuel injection, I have been looking at carbs lately, the Edelbrock VRS might be something I take a hard loook at.