I'm in the process of building 2 IMCO SC uppers. Does anyone know if IMCO uses a different size (smaller) race than what Merc uses in the bravo drives. The races, especially the inner races seem far to tight. There is no way to get the race in the drive unless you tap it in, which is going to make shimming the pinion gear a fun job and it seems that it would be all but impossible to get the yoke assembly out when the drive has a gear set in it. Thanks for any input!

I believe they are the same pinion bearings/races, I will check.
I rebuilt an SC Upper for a customer that was the same as yours, very tight, it was a real job getting it shimmed correctly because of the tight fit.

That's what I'm worried about. I've had a few Bravos that were tighter than normal and it was a bear to shim them. Both of these IMCOs are ridiculously tight. I had to tap the races in when checking to see if they were the same as Merc. To be honest I've been thinking about taking these to a machine shop and having the clearances open up; however I'm not sure if that is a good move.