Do you have wiring diagrams for the stock (305) setup and the transplant (454)???

Somewhere in that swap, you may have a different wiring configuration in a plug.

I have seen turn signal issues when trailer towing connections have been spliced into the wires. Also, check the flasher units. Some vehicles have dual flashers - one for turn signal and one for emergency blinkers.

Don't assume ground connections are good....

John Stewart
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