Intermediate housing bearings

The boat is an 1981 Seaswirl with a 120 HP OMC drive. Over the weekend I got a really bad noise from behind the engine and after finding no oil in the intermediate housing, I removed the intermediate shaft and found the bearings are shot. I've bought some new bearings (as well as new ball gears) and my question isabout setting up the preload for the bearings. If I simply reuse the shim that was there will that be close enough? I'm guessing the only way to do it "right" is to pull the engine out and use a torque wrench to measure the preload and then adjust by adding or removing shims. I really don't want to pull the engine and I have no idea where to get shims or different thickness shims.