For $3,900, I wouldn't even bother with a 4.0L. For that much coin you could move to a 4.3L or even a 5.3L. Means more work and not just one weekend. But then you won't be wanting more with a 4.0L... It doesn't make sense to swap in a 4.0L and stroke it or supercharge it when you could have a V8 and be done. With that much money, you could easily move into 6.0L range.