How many of you?......

I'll do whatever the customer wants. The only "maybe" in building an engine for a particular combo is the convertor. So much of it's performance is determined by the engine's output that if the original engine had any real unseen issues a better replacement may change the personality of that convertor. Otherwise it's not much different than building the whole powertrain... match what's there, match what the customer wants out of it, and you're good.