yeah, i did it. however, i still haven't gotten the cable tension to work right (this is with a versailles axle swap, and to be honest i haven't touched it since it was installed...).
didn't do any welding, simply bent two brackets and mounted them to the tunnel and bolted the 89 e-brake handle to the floor.
as far as getting it to work, my roomate has an 86 GT that he did a full disc swap onto (remember, 79-93 are all drum rear and 94+ are 4wheel disc) and in doing so, he had to weld a piece of the e-brake handle together to get the proper cable travel. might be the mod necessary to get it to work... there are pics on my site of the brackets and e-brake mounted in my car.