That means you will have to mate your 4.7 tundra motor to the Th400, tranny...You will also need to custum fit a matching GM rearend on your SC400 maybe.. I don't think the differential gearing on a Lexus rearend would match to a th400.....Bellhousing, etc...Not an easy task my brother, alot of welding, alligning on the rear and what not, custum made drive shaft for length fitment.. It is doable as I have seen it done once before on an 1992 SC400 courtesy of our old friend and pal Todd at TM Engineering....