Will a Dodge 3.3 liter engine fit into Neon?

No, a 3.3L engine will not fit in a Dodge Neon without significant and likely impractical modifications. The Neon was designed for much smaller engines, typically 2.0L or less. The 3.3L is considerably larger and heavier, requiring changes to the engine bay, mounts, transmission, and potentially even the chassis. The undertaking would be a massive custom project, far beyond a simple swap.