There's a joke that says "Every Yamaha is designed so that 80% of its parts come from existing models" - there's a lot that is the same and even more that is interchangeable with other models.
The YZ465G is the same basic platform that is shared with the YZ250G & H, YZ465H, IT250H & J, and IT465H & J. As a general rule, you can assume that parts from any of those bikes will fit your 465G.
There are exceptions, but it's a solid rule of thumb.
All of the YZ490s used the same basic motor, but there is a change from side exhaust port to centre port somewhere in the life of the 490.
More generally, here's a short list of the many parts that will work with little or no modification (rather than parts that are identical):
Front wheel = virtually every Yamaha MX or enduro bike from 1973 to 1985.
Front brake = virtually every Yamaha MX or enduro bike from 1977 to 1981.
Forks = YZ125J/K, IT250/465, IT175J/K.
Triples = YZ250D~G, YZ400D~F, IT250D~J, IT400D+, IT425.
That's just in front of the steering head...