People have done it but went go backwards? Few things to consider:
1. ABS
2. Transmission control
3. Cluster
Very possible and ive seen several builds on it but you can do just as much with a computer with more control and flexibility. Easier to start, generally better fuel economy, more fine tuning. SCT will handle anything from stock to twin turbo 408 running e85. Just my opinion.
But if you really want carb: 4bbl m1 or edelbrock intake, distributor change, brake system, A518/727 transmission or 5sp, mechanical gauges.
This isn't all but I'm far from being an expert on carb swaps and being a young guy, have very limited experience with carbs. In fact i don't care to, i like my efi. But again, that's just me.