57Becky brought up the anti oxidant compounds when using Aluminum conductors, here are 3 examples:
Penetrox (manufacturer Burndy)
De-Ox (manufacturer Ilsco)
Noalox (manufacturer Ideal Industries)
After stripping the insulation, wire brush the conductors, and apply a liberal amount of compound to each before terminating.
Also,if you end up using Copper conductors, eat your Wheaties. 500' of #1 THHN weighs about 150 lbs.
Good Luck.