Get a price on the lowest mile 3.7 from an autowrecker that you can find.

I just spent a bunch of money on re-doing 3 burnt valves on a Neon, only to find out later I could have got an entire engine from the local wreckers with 30,000 miles on it for $500

Might sound extreme, but it takes the same amount of time and I would have had a "do-over" for the car.