My engine is spaced up about 1 inch more than the factory FE. The trans barely clears the trans tunnel. 3/8 inch maybe. My U joint angles are slightly too much. I don't see how you could raise the engine 2 to 3 inches and not be way off on the angle of the output of your trans to the angle of your rearend yolk. I hope this helps.

69 mustang, 1977 460, 1970 heads-home ported, 213/224 dur-.512/.535 cam, Edelbrock performer intake, 800 Edelbrock carb, stock exhaust manifolds, factory dual exhaust, TCI 11” converter, 3.50 gears