Engine dies

[CW4B]

70 C20. She’s very rough, never run well/smooth since I’ve had her but today engine kept stumbling, spitting & sputtering then dying. Particularly when more loaded like going uphill and more so when it shifted into 2nd. Like it was running out of gas. After stopping and putting in park, she would start right up but run rough and sputter again and die after a bit of driving.

She’s been sitting for awhile, maybe a year without much operation, but I did originally drain tank and put fresh gas (1.5 yrs) and recently filled it up (only 4 gal) and she has a remanufactured but original carb that I “tuned” IAW instructions using a vacuum gauge. I also had installed a new fuel pump and replaced all rubber hoses in fuel line. Haven’t checked fuel filter but it came inside remanufactured carb. Also have installed EFI in lieu of points, new distro cap, wires and plugs.

Not sure how the begin troubleshooting. Seems like many overlapping sytems it could be. Fuel? Carb tune? Spark? Timing? Distro (vacuum) Timing chain?

Help? I plan to rebuild the engine & rewire everything, but hoping I could drive it in town for awhile for now.