Hey all. I just bought a 72 cuda this last weekend.
Here is a rundown about it.
340 bored out .40 over
- how big does that make it?
-is it a hemi?
4spd but origionally aut
6bbl carb originally 4
NO rust 
New red factory color paint inside and out
Brand new covered interior in grey hd cloth
All new glass rubbers and trim throughout.
Bad:
Brand new motor hasn't been tuned and has a slight miss or backfire and carb hiss
Grill was stolen 
Tiny stock rims ew
Air shocks in the rear bit need new lines
Other than that it's a NICE. About as nice as you can get and not feel bad about driving it!
Payed $15,000
With the .040 bore you gain approx 4 ci so 344 ci
seems like a reasonable deal , as long as the body is solid ! You got a drivable car converted to 4 spd for 15K , what could you get new for 15 ? Even a used Honda would be 3/4 of that . A new 6 pack system is $2200 minimum , a 4 spd conversion is around $4000 to do
sounds like you have a vacuum leak , to remove the carbs you start at the rear , split the fuel line at the tee under the center carb , probably nothing too serious to fix , tuning is easier than most people believe , just think of it as a 4 bbl , most of the tuning is in the center carb , the secondaries work together .
The grille will be the biggest problem , originals have dried up , not sure if there is a repro for the 72-74 yet , you might be able to fit a 70 grille though & they do make repro 70 grilles & header panels
