Years ago when Hensley built my first stroker( 416) i asked Ken Hensley( who i have a ton of respect for) what difference there was between a 340 and a 416 all other things being the same. He said 3 tenths. Never forgot him saying that.
Real world, my 360 has run 11.20's at 10.4 compression with mild eddies at 3300 with a 727.
My little brother has a new 416 with max effort Shady Dell eddies, 12+ compression, same weight, and he has a 904. Admittedly he is having teething issues with it, but thus far he has been 10.95 at 120. 1.5 mph faster and 3 tenths quicker, and he has a 904, which is definately quicker. I am sure it will run a good bit better, but so would mine with a 904 i have on the shelf and a convertor correctly specced( one in car car now is a tight 4500 flash) devinately "off" with what i have.
So yea John, i agree. Why toss that huge crank around for not much gain. 4 inch to me is more than plenty.