Do you have a 231 sittin' there also? Measure the OD of the input shaft and tell me its size with a set of micrometers, not calipers. There's no need to go figuring out a different seal in there. That'll get me started. I was yappin' with Dad about it at the dinner table and he seems to think that broaching is going to be the best approach unless I was to make 20 or more ( can you say $$$$$$$$$$$) I'll have a 231 and spare AW4 in appx. 1 month to work off of. That's when I was going to start dinkin' around with it.
To be honest though, for my needs the TF999 or rather the 32rh is going to be the better route for me. I assume you want to keep the OD of the AW4 for street use. I've been watching the posts on the various boards, it seems as though we are both trying to chase down the same obstacles right now.