The torque and off idle response of a big inch Hemi along with the top end pull is the best combo on the planet!

But, as you have added information and again mentioned that you don't want to romp on it, then you might just as well stay at 426. For most cars, there is no traction with a big inch Hemi until 50MPH anyway.

FYI: Barton spec'd my 540 with 10.25 compression. Does fine on 91 octane.

So:
Pros; added torque and throttle response in a street car
Cons; more money, additional traction issues