[SSSammy]

Jim was referring to the face of the tranny being flat, btw, not the spacer. I'm not sure filing the spacer was called for .. the spacer could have been a tiny bit warped. This happens when metal is machined in a constrained state, then released. But when bolted up it would have been forced to be flat if the face of the Tremec and the BH face were truly flat. It is made of soft aluminum.

Again, critical concentric alignment is controlled by the registration ring on the BH, the lip on the spacer, the registaton ring on the spacer, and the outside diameter of the bearing retainer flange (collar) on the Tremec. All of these slip fit together in a stack.

I am a little concerned about the input shaft measurements, not having any experience with the stock BH. Are you saying, according to your measurements, that if you bolt everything up, the input shaft will not penetrate the hole in the pilot bushing? Rather that it will just barely touch?

If this is indeed the case, the spacer may not be required at all with this BH, since 5/8" is about how thick the pilot bushing is.

I really would give Doug a call Mon and go over it all again with him, make sure he understands you are using the stock FE bell housing.

Sam