What's 300hp get you in the 1/4 mile, somewhere in the high 12 - low 13 sec at 104-105 mph range? Does that seem possible with that combo? Not really to me.
Those calculators say a 275 hp 340 duster should do low 13's stock (12's if you believe a stock 340 makes more hp), funny how math (based off what ?) is considered more accurate than a purpose built measuring tool that cost idk $100k + ?
Here's 318willrun's 14.04/96 mph 318 4bbl, headers, small summit cam, pocket ported, 2800 rpm stall and 3.55.