B1 Shootout: KSB1B vs. KSB1 vs. B1B vs. Full B1

[Hohn]

Ok, what's the rank order of of B1s from fastest to slowest spooling? I am under the impression that it's:

KSB1B- super duper fast, but chokes after 425hp or so
KSB1- not quite as fast, but has longer legs to 450hp.
B1B- a little slower still, but will cool 475hp and pull hard
B1- SLOOOW but handles a LOT of fuel and will cool 500hp.

How big of a spoolup difference is there from one flavor to another? Which plays a bigger role in spoolup, housing size or wheel size? (the above assumes wheel size is a much subtler change than housing size).

Has anyone changed from one variant to another and found what you were looking for? Can you swap housings like you can on a Holset? For example, if you get a B1B and decide it's too slow, can you just swap housings to get a KSB1B?

I've determined that a B1 is the single charger for me, but I'm not sure which flavor just yet. Right now, I'm leaning towards a B1B. R.ebel puts down 500+hp with his, and it's got enough spoolup to tow in the Rockies at high elevation.

Any inputs from the peanut gallery?

Justin