i should have not worded it that way not my strong suit
you will have a better carb cam exhaust and traction that will help you exceed the power needed to run your number as compared to the factory 340 setup
timming on a stock 340 was soft as well
a strong stock 340 setup right intake 650 dp or thermoquad 2 1/2 exhaust good 60 foot is a mid 13 second car you will have all that plus some roller cam etc
just 22 cubes less so it might equal out
260 270 hp@ 3600 lbs gets you in the 98 mph area thats 13.9 with a 1.9 60 imo