If you have a tight fit, the best thing to do is get a fitting template from the manufacturer. It's a view of the motor from above that shows the part that fits into the bb and the chain ring. You print it out. Make sure your printer doesn't resize it. There will be a reference ruler on the diagram. I use the diagram to cut out a stiff version using coroplast or cardboard. Remove the bb and fit the template into place, it will tell you if you have the clearance or not.

Spacers will move the chain ring outward and may give you the clearance you need, but this approach has problems. Look up "chain line." If you move the chain ring too far out, your chain will drop to the inside when you go to the largest cog in the rear.. A chain guide or chain catcher can help with this. Some people remove some of the cogs, bringing the largest cog away from the hub, but you lose gears. It's a pain in the butt and can be difficult to solve. You can also run out of thread on the side opposite the spacers.