928 vs 944

i was looking make a project track car, and was not sure which to pick 928 or 944 turbo. I was planning on replacing the engine with an ls 1 so engine reliablilty is not a concern. mostly i was wondering which would give me more space to work, which is lighter, which will be faster, which is easier to work on, and which can handle more punishment. I would also like two know what the main differences between these two cars with the exception of the engine and body style. all help is appreciated