You didn't really mention what your power goals and use for the car are.
Heck, build the biggest engine you can afford, slap a set of twin T76's on it, and let'er rip. You have also saved for the heads, cam, intake, cooling system, fuel system, engine management, tranmission, drivetrain, suspension, and interior mods you will need, correct?
1990 LX Coupe 5.0 5 speed w/ 2000 Exploder GT-40 engine, P heads, mystery cam (F cam per previous owner) 3.73, and not much else. In the parts pile - UPR tubular K member, CC plates. Future plans - Megasquirt & On3 turbo system.