Yes, I seem to remember reading that as well about Mc Leod. IIRC, the difference between the mod and the w bellhousing has mostly to do with the starter location.
But anouther big problem in using the T45 is that it is designed to use a electronic speedo. So the pick up is completely different as we're use to. They don't use a drive and driven gear to operate the transducer, they use a star wheel and the pick up is perpendiculat to that wheel, meaning that there is no way in Chevy land that you're going to use or make a gear drive mechanical speedo work! Electronic only!