budget street motor 360 or 383 for 71 duster

I just gotta ask; why are you targeting so much power, in a car that is limited to just 65 mph, and won't hit 60 at any agreeable rpm with street gears, and even a hot teener combo,can spin the tires all the way there?
Look, I got a pretty tame 360 in a 68 Barracuda, that spins 325s to well past the speed limit. 450 in a streeter is waaaaay overkill. 300 is all you need with the right gears. 350 is plenty with 3.55s
You know you can stroke your SBM, to somewhere between 370 and 388 cubes, with a 3.79 crank right? .......Just add a small fast-rate FTH and you'll be singing the No-Traction-blues.That and an A500 with 3.91s and ...............winner/winner/ chicken-dinner!