340 or 440

Street-cam low-deck BB/auto /and 2.94s; done. Torque is addictive.
340s were something special, once; before 360s, and when 318s were were just mules. But in this present history, almost forgotten.
Torque is still addictive.
340s and torque, rarely appear in a streeters vocabulary.
What does tho is; " I got this driveline vibration I can't seem to find". Well yeah, 3.91s or better has a tendency to amplify any existing vibration, that was minor with the 2.76s,lol.
Or; "man my 340 is hard on fuel", I couldda run a 440 on less.
Well yeah your effective stroke is down to 2.5 inches,lol; whadya expect. 20% or 30% of the energy in your fuel is going straight out the tailpipe; that's what happens with a very early opening exhaust valve and a 3.31 arm.
I'm not sorry I chose a 360, but I'm sure glad it is at least a 360. Second gen Barracudas are the fatboys of the A-bodies, their saving grace is in their beauty, and their ability to accept 295s back there; even 325/50-15s...... inside the stock tubs.
451 cubes, yummy. Run the auto to suck up any vibration, and street gears to let the torque get you moving. Cruise at 2250 or less for excellent fuel-economy, relatively speaking. With 2.94s you can hit 60@ ~5600 in first gear, making it a one-gear run.

Since you have a clutch, you could run the A833od and a lil more gear, as if you need it. That will let you downsize the cam, and with 3.73s now, you can cruise 65=2200 Badaboom. Buy a spare trans or two, cuz if you are used to driving 4-gear, you will blow up the od gear almost right away; it was designed for a 318/slanty so it's kindof puny. I went thru a couple before I got rid of the 4.30s, so stopped powering into "4th",lol. Zing.