Cool, I'm glad it fit. I hope you made sure it is square to the body before welding. I never actually pulled that bracket out of the donor car. When it looked like it wouldn't fit I didn't bother. I also wanted to keep the donor together because I thought I'd be selling it more or less whole (which didn't happen). Can you get pictures of it and where the shaft and bearing end up at? I'd suggest just tack welding everything until it is all in place. You really want to keep the shaft as straight as possible.
In the GSX the front hanger is directly under the brace where the front seats bolt down. It is a well reinforced part of the car. I put it there and would suggest you do the same. You'll need to do a fair amount of trimming to make it work as the two tunnels are VERY different at that point. After you get that right then worry about the shaft lengths. If you fudge just a little bit to keep one section the same length it is probably fine but I wouldn't go too far from that area. Oh, and pull out your carpet so it doesn't catch fire :)