Finding (calculating?) speaker and amp impedance

@barts I was referred to a gentleman on AudioKarma that specializes in vintage Sansui. He stripped boards, removed all old corrosive glue, completely recapped in addition to countless other parts, extensively tested, adjusted bias, burn-in, more measurements, etc…and kept me updated with details and photo’s throughout the process. He’s in a small town in Mississippi and prefers not to ship equipment. So, a 10 hour round trip for drop off and retrieval from here. 
 

Bottom line, it’s more of a hobby for him than a business. I’d want to check with him before passing his name along. 
 

Good timing for this topic. Using a pair of Focal Aria 936’s with a PL HP Integrated and all is good. But…I just had my 45 year old Sansui AU-717 fully restored and it’s in transit as I type this. Per Stereophile’s review, these speakers drop to about 2.7 ohms in the mid/bass region, yet publish as 8 ohms nominal. The PL tube amp handles it just fine in either mode (70 wpc in ultralinear, about 40 wpc in triode).

Im eager to try the vintage Sansui in this system upon its arrival. Bad idea?

@barts Sorry…I should have been more clear. My wife went to visit her mom this weekend…about 2 hours from his location. She picked up my amp on her way. I married a good woman!