I've got a 996 75mm TB on my car. I used an aftermarket piece of flexible intake ducting to connect between the new TB and the MAF, and the tubing just barely fit. I've got a feeling that if you used tubing for a larger diameter TB you might need to do some body surgery to make it fit. Good luck!
BTW, I didn't lose any torque. Actually, the mid range seems to be where I gained the most.