Is a Strange S-60 more efficient than an 8.75", as in enough to help offset (some of?) the weight difference?

I'm trying to calc some target ET & MPH #s for my new combination. I know the Strange S-60 conversion has added some weight (not sure exactly now much; estimating 50#s) compared to my old 8.75". Neither old or new diff use spools; 8.75" had Power-Lok and S-60 and Strange has S-Track.

However, I've read here that a Dana 60 is more efficient than an 8.75" and the ETs are usually very close, despite the weight increase. True?