My impression is, if you have not run the car, that you are not in the 14s now with what you have. If the engine is a good running '77 440 non HP, you have a good base, and one that can get into the high 13s with the properly matched driveline. a 2.76:1 rear axle ratio is not "propoerly matched" if your goals are 13s and you have a stock engine. 1. You dont mention the exhaust system... If you have manifolds, replace them with headers. Cheap headers are available for that car so long as you have a floor shifter. Have a good dual exh system bent up. 2 1/2 in pipes and decnt mufflers are plenty.
2. Replace or re-curve the factory distributor, if it is lean burn, get the MP electronic conversion with the vacuum advance.
3. Replace the center section with a set of 3.55s. They will allow for decent highway manners and not hurt the 1/4 mile work.
4. Install a shift kit in the transmission. I like Trans Go myself. But anything will do at this level.
5. Replace the timing set, camshaft, valve seals, and valve springs all at once. Something like the Comp XE262, or the "larger" Summit Brand cam, and a set of 911-16 or Edelbrock take off springs would be fine. The timing set from the factory has nylon gears which tend to break and shear, so ditch that too.
With those steps, done in that order, and your current intake and carb you will get the car into the high 13s provided it's tuned well and the tires are sticky. The carb's size is fine. Spend money where you need to, not where you're workable already.
You do not need to break into the engine beyond the timing chain cover if it's running well.
A similar build with a slightly larger hydraulic cam and 3.91s went 12.40s and I drove the car for two years daily. Including in the snow, with a '78 pass car 440 with 80K miles.