Main Bearing Clearance

Rodzilla, what is your intended purpose of this build? This question is key to you getting the clearance you need. .0015 is fine for street with the correct oil viscosity for your temperature (read this as NO 20W-50!!!). Are you driving in winter? Are you drag racing? What is your redline? What type of oiling system are you using?

These questions need to answered before I can give you some guidance.