1972 Demon 340 engine mods

i don't know about all the work and money these guys want you to spend.
I see it has 14" tires and probably 3.23 gears.With that i would suggest leaving the cam alone.I have driven a few stock 14" tire 340 A bodies and if well tuned they pull very hard on the street.
Maybe that thermoquad isn't working right and may have vacuum leaks.I'd start by recurving your distributor and putting on a new 600 carb.
Perhaps replace the three speed with a 4 speed and tune...tune...tune.
That car should run hard on the street and take no prisoners street light to street light

Rear end is sure grip with 3.55 gears, check above.
Wheels will be swapped for 15" rally (to keep the stock look) with 275/60/15 on the back and 205 or 225 front(dont remember).
Carb on it now is holley 650 with vacuum secondaries. There are no vacuum leaks or anything.
For me this car actually runs really nice and strong, but after he had a ride in my Duster with big block he wants more out of it.
The good thing is that he does not want to go all the way and only mods will be done to the car with parts that you bolt on. This is the only reason I am involved in this.