Does it have a stock Mopar 4 speed trans and 3.73 gears?
25 or so years ago I had a 10.5:1 340 in my 68 Satellite running 11.60’s@117........ but it didn’t have a 4 speed and 3.73 rear gears.
I guess we’ll have to wait for clarification....... I thought it was a typo for “833”.
If it’s an RPM headed 433 in a small car like that, and it’s set up even 1/2 way “right”, it should go 10’s.
Going quick with a stick car is mostly about “the car”.
Making enough power with a stock stroke 340 to run 11’s in a 66 valiant is absolutely “no problemo”.
It’s the stick that throws the wrench in the works.
If it’s a “race car”, it’s easier....... you buy all the good stuff so you can leave at 5 or 6k and not worry about it.
It’s a very tiny fraction of the stick shift street/strip combos that have the good stuff between the crank flange and the axle flange.
On my buddies stick shift Stocker....... that stuff costs way more than his motor does.