imho, dont waste your money on 40s, they are too small for a 2ltr Pinto. The max choke size is smaller than an inlet on the head. Save a wee bit longer and go for 45s. They'll support circa 190hp should you wish to increase performance in the future.
I'd fit a 38 or bike carbs before 40s, but bike carb set up can be expensive if bought new.
I ran a bike carb/megajolt set up on the Green RS in the pic for a while - all 2nd hand, and was well worth the coin. Ran like a sweetie, had circa 160hp and sounded the dogs balls on the cam.
Previous car had 45s, RL31 cam and monster valves etc. 187hp, pulled like a train to 8000rpm and had a bark louder than a scrap yard rottweiller!!!!!
Get yourself to a local Stock Car builder, they'll show you what kind of power can be produced on a stock carb!!!!! (with supporting mods obviously!)