No, the tail housings are different. While some T4's did get the T5 tail (my guess is BW ran out of the T4's) the majority of them get a 4-speed specific tail. No cavity for 5th gear. If you got one of the T4's with the T5 tail, you fount the proverbial needle in a haystack.

The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me