Rick,
Congratulations!
After you get a chance to ride it, I'd (and others I'm sure) would appreciate a comparison of your two 3 1/2's performance capabilities. This Cycle World review of the 1980 model said it was two seconds slower through the quarter mile than the 1977 one they tested:
https://tinyurl.com/1980moriniCWreviewBut I understand your K2 may have had higher performance.
Also, do your two bikes have different wheelbases? Online sources (e.g., classic-motorbikes.net) say the wheelbase (apparently for all years) was 1371mm (53.98 inches), but Cycle World measured the 1980's wheelbase at 55.25" (1403mm), or 1 1/4 inches longer. I trust Cycle World more than the average internet site. If you could measure your two wheelbases to the nearest 1/4 inch and report what you find, I'd be very interested.
Sorry if my questions about your new purchase seem too intrusive! Enjoy your new bike! Congratulations again.
Moto