4 ohms to 8 ohm speakers?

Yes sometimes a speakers ratings is a average and could very possibly have dips very well below its 8 ohn rating use the ear to be the judge.

Groundhog,

See this recent thread on the same topic. Bottom line is try it and use which ever sounds best. It will not hurt your amp or speakers.

Use of 4 or 8 ohm tap?

Changing from 8 to 4 ohm has certainly made a major improvement.More pronounced bass,more clarity and a more realistic sound.
I hear things that were dubbed before and now it seems there right up front where I hear them perfect now!
Thanks for the info........
Peace

Of course the tap that sounds the best to you is the one to use, but the one that sounds the loudest indicates the most efficient power transfer, and potentially lowest distortion. But this factor will be all over the map with different speaker/amp combos regardless of nominal ratings, so experimentation is the only way.

For some reason the link I provided doesn't seem to work, at least on my PC.

The thread name is "Dunlavy 4 or 8 ohms for Audio Research VT-100 amp?". You can do a search for it.