Do you already have the borgeson box?

The engine going anywhere for work is going to cost money. What does a Leakdown test show? Where's the air leak? I'd do the absolute minimum to get running like it sits. Get to driving and having fun.

I'm not voting you go with a Hemi, but fyi, Hemi swaps can be cheap. 300 rwhp with log manifolds and a bone stock early 5.7 (with manual steering). Or 400 rwhp with a bit of work and headers. If you already have the borgeson box, then buy the TTI's and get out your hammer. Fits on my car. I highly recommend putting the motor in from below. My second piece of advice for those reading- if the headers don't fit with the TTI mounts, modify the mounts to fit the headers. Emil did that and has pretty headers. I did not and I do not.