Is your amp a tube amp, A/B solid state, or class D?
8 ohm speakers should be fine with any solid state amp, regardless of whether A/B or D. Tube amps generally have an output transformer that has one set of speaker terminals for 4 ohms, and another for 8 ohms (and sometimes on older models, also 16 ohms.) With a tube amp, try both and use the one that sounds the best.
Problems sometimes only arise from the opposite scenario -- 4 ohms speakers with a solid state amp rated only for 8 ohms. This setup can sometimes overheat the amp.