Have you decided on your front suspension yet?
On the Mustang II setup I'm running and the other Mustang II based units I've seen, the crossmember you weld in lines up with the center of the wheels and uses a front mounted rack. The rear sump pan will work with no problem and the center sump would probably work. If you're using some other suspension especially one with a rear mount rack the center sump pan may become a problem.
As far as the exhaust, the exhaust on the second engine looks like it might be a bit wide to fit but that will depend on the height you set the engine at. The exhaust on the first engine might work better but it could get a little tight making the bend required to clear the firewall.
Either one could present a challenge getting the steering shaft(s) connected between the column and the steering rack. One of the things I found on mine was that clearing the back of the block was almost as much of a problem as getting it past the exhaust.
In spite of how it looks it does turn smoothly and with the power rack there is not a lot of strain on the joints. If I ever redo it (or had it to do over again), I would probably look at using a “Steer Clear” box drop and eliminate the upper steering shaft.
http://www.wizardsteerclear.com/.
