Time to Fix It Right

I've been a member here since I got my 73 Duster back in 2009 as a high school senior. Kind of hard to believe I've had her for 11 years already! We've had some awesome times including a 10-day road trip down Route 66 when I moved to CA for grad school and having her as my daily driver for my first 3 years out there. I haven't been on FABO much for 6 or 7 years as I never had the time or place (or $) to really work on things while I was in school, other than a radiator swap.

These days I have a (small) garage and I am blessed to have a few more disposable funds. Also will be hitting the big 3-0 milestone later this month. I still cruise the Duster every now and then, but I always feel a bit on edge when I do -- the list of "tricks" I have to use to keep it running gets a little longer every year.

I think it's time to start doing some real repairs the right way, not the way I did them when I was 20 and looking for easy answers. And, while there are many things that need a bit of work (tires, body, interior), the one that impacts me the most & where I need the most help is getting the engine running like a 70's V8 should.

At some point I'd like to do a full-on rebuild (engine swap, crate build, something like that). I don't feel I have the space or money for that right now -- that said, there's a cost to patching things up, and in this case maybe the full rebuild is really the only thing that makes sense. That's part of what I'd like to figure out!

Goals (for now)

• Cruising. I would like to be able to go for a drive without stalling out at intersections or overheating in traffic (to the extent that this is possible in a ~50 year old car).
• Understanding. I'd like to know what the underlying issues really are, what adjustments I can make, and what the response to those adjustments should be.
• Safety. Night/rain driving are a bit hairy with no cabin air controls and an engine that runs noticeably worse with the headlights or wipers on. That was fine when I was younger, but now it really limits how often I go for a drive.

Current Problems

• Neutral idle has to be set to ~1500 RPM to avoid the engine dying in gear.
• Stumble (miss?) on light throttle cruising (say, 30-45 MPH)
• Engine takes a second to go after a big throttle increase
• Engine runs worse with headlights on -- more likely to die at intersections.
• Seems to run OK for the first few minutes after cold start, then get worse as it heats up to operating temp.
• Hard to set timing. Seems to wander a lot on idle.

Possible Causes

• Mis-matched setup (carb/engine/cam etc. just not right for a street cruiser)
• Carburetor tuning (I've tried doing this but not with enough patience)
• Engine in need of rebuild (a specific problem e.g. jumped chain or just old)
• Electrical system (battery/regulator/resistor/coil new, everything else old)

Technical Specs (top of my head -- will add to this)

• 1975 360 V8 ("built" and swapped in before I bought the car)
• Stock heads
• Comp cams Magnum 280H
• Holley 670 CFM Street Avenger (vacuum secondaries, electric choke).
• Electronic ignition (stock, I think? It's a distributor but doesn't have points).
• Stock intake manifold (I think I plugged the EGR port at one point, though).
• Stock exhaust manifolds, 2.5" pipes with an X crossover. Driver's side has a 2" section as the shop I used couldn't bend 2.5" but needed a custom piece there.
• 904 transmission, stock torque converter (as far as I know)
• 7.25 rear end w/ either 2.76 or 2.94 gears, not sure which. Runs ~2800 at 70 MPH, if memory serves.