I swapped a 4.3L for a 305 I with 350 heads, .470/.480(big for a 305 I know) cam, Jet stage 1 chip, 350 throttle body, and Hedman headers. Already have a NGK O2 sensor and a ACDELCO idle air control.
But my problem is turning it over it starts up and runs good till you put it in gear and it...