For hub-piloted wheels, you either need to change the studs to longer items for the aluminum wheels, OR you need to get a special wheel and nut combination.
The special wheel has oversized lug holes, and the special nuts have sleeves on them that thread down inside the enlarged holes.
You can't simply buy the wheels with the regular size lug holes and then hope to find some kind of nut that will work -- there will not be enough threads engaged to be safe or legal. If the wheels you bought have holes just large enough to clear the studs, then you will need to change the studs to longer ones.
Also be advised that whether you can dual aluminums or not depends on the depth of the pilot lands. Many pilots made for steel wheels will not have enough depth to engage the flange of the outer wheel if the inner wheel is aluminum. For this reason many folks, myself included, have to run steel wheels on the inners.