Be careful of accelerated wear on your chainrings if you use the wrong chain, one designed for more speeds than the the chainrings/cogs you are mounting it on.

Cog/Tooth Width (From Sheldon Brown)

• 8 Spd: 1.8mm
• 9 Spd: 1.78mm
• 10 Spd: 1.6mm

Chains from 7spd and 8 speed are the same. same spacing, same cogs. the rear cluster is just wider, and the wheel not as good structurally as a result. 8speed is popular out of china no-name factories and is junk that should be avoided.

Having tried to use quality SRAM chains I had, on clusters that are designed for less gears than the chain is designed to be paired with, I can attest that most of the time, the chain won't even go down onto the cogs and won't seat itself properly.