Not possible without a custom bellhousing. The T45 bolts to the bellhousing from inside the bell, so when you pull the trans, the bell has to come off with it as one unit. The problem is that the bolt pattern is different between the 4.6 & 5.0.
The T-45 is a POS anyway. I broke two in my Cobra in less than 8K miles. I broke the 1-2 shift fork in the first one. And then Ford warrantied it and put in a brand new T-45. 8000 miles later, I broke the 3-4 shift fork in it. And yes, that was with an aftermarket shifter. I have yet to break any of the T-5's I've owned.