I am running a similar set-up to Journeywork. Sniper, MSD magnetic pick up distributor, a MSD Blaster SS Coil, Sniper coil driver (instead of a big MSD 6AL box), Edelbrock top end kit on a roller cam 302 block, and a spectra EFI fuel tank from rock auto. Cold starts instantly. Revs to 2000 RPM for 2 or 3 seconds, then down to my target of 800.
My car was a shell so I needed a fuel tank, fuel line(s), fuel pump, and either a new Carb or EFI. Fuel tank is a wash vs carb (includes the pump), need one extra fuel line ($100 in material), same intake, and $500 more for Sniper vs good carb. Cost if you're in my situation isn't that material.
I followed the Holley video on how to set up the distributor, and how to wire for timing control. My only issue was I wired the coil driver wrong on first start attempt. Once fixed, it coughed and tried to start. Had distributor 1 tooth off. Reset that and fired instantly. Perfect idle, super responsive, good AF, fans kick on and off perfectly, etc. Static timing check was dead on balls accurate at 12^ at idle (slightly advanced form a stock 5.0 at 10^). 32 degrees total timing to start. I love making a change on the handheld to change parameters. Getting detonation? Change timing. Have a stumble at X RPM? 5 things you can set to change it. Want to advance timing? Done in 5 seconds. Running rich or lean? Can see in real time and fix it. I am still learning the power of the system; pretty amazing. If you like jets, floats, bowls, idle set screws, mixture screws, etc then EFI isn't for you. I'm going to hard pass on all of that.
Regarding all the "gas smell" comments, just note there is "gas smell" and there is "my car has no catalysts like a modern car" smell. I have zero gas/fuel smell, but my 67 Sniper car will stink up the garage just like my 92 Fox body does with an off-road H-pipe.