69' Dodge Dart Resto/Upgrade in NY

Like what, besides motor mount adapters, custom headers, mini starter and disc brakes up front?
Like Steve said, torsion bars. But you'll pile up the bills pretty quickly as that stuff has gotten expensive recently. You'll get close to $2K PDQ. TTI headers $1000, disc brakes figure $300-$800, motor mounts brackets $150 if you can find them, starter $80-$150, torsion bars $325+... Since Schumacher's engine swap stuff isn't available for now, you'd need to scrounge for stuff. Maybe find a Direct Connection big block K-member, also expensive.
But a 440 Dart is a sick car!