The 3.8L takes a BOP bellhousing but it is pretty compact. I used to have a CJ-5 with a Buick 225 (same dimensions) shoehorned into it, it actually had enough room under the hood to work. With a 4bbl Qjet on an Offy manifold it was scary fast- the Jeep only weighed about 1800 pounds.
I don't know how you will fit the turbo in there but if you use a passenger side exhaust manifold on the driver's side for a front dump exhaust you don't have to move the steering box.
