It'* not a simple answer and there are a couple different directions. It'* not just a slap it on issue at all.
The base differences between the two motors are:
1. Compression ratio (9.4:1 for yours, 8.5:1 for the L67)
2. Lower Intake Manifold
3. Pistons and rods
4. Cylinder heads
5. Fuel rail and injectors
9. A handful of smaller items as well
From a reliability standpoint, the best route to go (and probably financially as well) is to simply do a full swap of the entire drivetrain. Engine, Trans, Axles, PCM.
None of the options are 'cheap' or easy by any stretch of the imagination. So let'* get an idea of your budget and your skill level before we go further.