Few questions for the early A gurus

1. Are the heater box assemblies the same 63 to 66??

Not sure if they are the same or interchange.

2. Are 65 valiant hood and fenders the same as a 65 barracuda

Yes

3. Is a valiant wagon rear bumper the same as a valiant 4 door rear bumper?

For 64-65 Yes (part number 2266602)
For 66 No (‘66 SW is same part number as 64-65)

4. Are the windshields the same between 2 and 4 door valiant?

Yes