shimming engine bearings

[norcalal]

Model a engine had a rattle starting with just medium throttle in second gear. Center main was over .003 then, brought it to.015, spun fine, I took a shim out of one side of the rear main, now extremely hard to crank, but starter will turn it freely. PlastIguage shows .015. don't want to burn up a bearing, should I reassemble with too much clearance according to specs? Please advise!! thank you