Can Dynaco ST-70 Drive Polk Monitor 10?

I have an ST70 and looking to buy some Polk Monitor 10 for a good price. I think the polks are rated at 89db at 8ohms. Can the st70 drive them efficiently?
I'm pretty sure that you should be fine. I've used ST-70's to drive speakers anywhere from 85-93db efficient. I will say that most of the less efficient speakers I've used were simple 2-way loads, so it's possible that the 3-way/4-driver load of the Polks won't agree with the ST-70, but I think that's unlikely.
I don't think there will be a problem driving the speakers, but....

While the Polk was a great value in its day (IIRC - and it's been a long while), it always struck me as just a bit soft in the bass. Similarly, the ST-70, while a really great amp in many ways, is not the last word in bottom end grip. So....while this might not be a match made in heaven, I'd still think it would be kinda cool.

You should be fine. I drove a pair of the Polk Monitor 7b with a NAD 3020 rated at 20 watts per channel (though it was very conservatively rated). When I bought that pairing I auditioned the 3020 on a set of the Monitor 10s and went with the 7s due to size and finances. The dynaco should work very nicely.
Yup 3020/10s - first system out of college - oh, yeah, and a Thorens.
I owned the Polk Monitor 10 for about 15 years. Most of that time I was driving them with my Fisher 400 and they are ok. I now am using a PACO/Jensen TR-10 combination. I wish I still had the Fisher/Polk to so some comparison testing as the Jensen may not have the bass of the Polk but sound better for my listening choices. I have an older HSU VTF2 to supplement the Jensens when needed. If its going into a smaller room I liked the smaller version of the Polk 5JR or Spica with a tube system.
A lot will depend on the size of your room, how loud you like your music, and the dynamics of your favorite music genre. No one can guarantee your satisfaction.
Thank you everyone. I have not been able to land the polls yet but wil keep you posted. lo looking at A25 and othe efficient speaker options.