Have you looked at this site?
Steering column 1968-69 : MG Engine Swaps Forum : The MG Experience Archive
When I was a kid this young guy in my neighborhood put a small block Chevy in his TC.
D'uh
I had a clean, pre-rubber bumper MGB-GT that I'd love to still have with an upgraded motor that wouldn't destroy the weight distribution and turn it into a tractor (see the travesty MGC).