Dave, hope this info. helps... Connections between aluminum and copper wire need to be handled specially. Current Canadian codes require that the connectors used must be specially marked for connecting aluminum to copper. The NEC requires that the wire be connected together using special crimp devices, with an anti-oxidant grease. The tools and materials for the latter are quite expensive - not practical to do it yourself unless you can rent the tool.
| [Note that regulations are changing rapidly in this area. | Suggest that you discuss any work with an inspector if you're | going to do more than one or two connections.]
I would eliminate the aluminum wiring all together if it is an option--it is not safe.