If your sure you will always be happy with the results of the SB stroker then go for it up
if not think twice about the future now work twocents
The reason I suggest that is you can't get much more C.I. out of the stock type 360 or 340 blocks, making a 400 block have 518. C.I. is easy up work shruggy
I've made 514 HP on CA pump gas with a 418 C.I. 340 stroker motor with a set of mildly ported W2 race heads, I made 612 HP with a pump gas 400 stroker motor that was 511 C.I. with a set of OEM iron 906 heads that where mildly ported with larger valves by the same head porter in SO CA work
You can make 2.0 HP per C.I. on both types motors, I built a B1 headed 544 C.I. motor that 920 HP on race gas in the Boise, ID area several years back with out a lot of effort on tuning it shruggy
You get to choose your type of motor up
But I'm a BB guy whistling

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)