I got a Teague Bravo cap to switch out the stock unit looking to give the drive all of the help it can get. The caps look like they are machined identically, so do I just reuse the shim that was existing under the stock cap, or is there some measuring and hammering to be done?

Use a depth mic and check to see if the depth of shim seat is the same in both caps if not add or subtract as needed. Make sure bearing tower race is set with correct tool for the gear set ( measure the old cap tower race depth).

Are you talking about the needle bearings?

the bearing race for the bearing inside the top gear...it goes on the outside of the tower on the cap.

It's the area where the shim sits. In parts look up its called thrust bearing even though it's a shim.

Tower bearing race is the one in the center of cap. Look at its location on old cap. They are set at different heights on tower depending on Ser# or on the gear set that's in drive

The wide outside thrust bearing is what I was referring too, but the needle bearings in the center height do look to be set at different heights. This would depend on the gear set?

Yes to question. Where your finger is if depth is same use same shim. Tower is race in center did new cap come with a race on it if so is it sitting a little lower on the tower than the one in picture, like it's not as high (the race it's self. If you want PM me I'll give you my cell# I can explain a lot faster than typing.