Is there anything extra required to spin a Cessna 172 in the Utility category?
Provided you meet ALL of the requirements for utility category operation as spelled out in the POH (within W&amp;B limits for the utility envelope, no aft passengers, empty baggage compartment, and anything else you may find in the Limitations and W&amp;B sections of your POH) a Cessna 172 is approved for intentional spins, and may be used for spin training.

As to the gyro instruments, spinning MAY cause the gyro instruments to tumble. This is not good for the instrument (it beats up the bearings - do it too much and you'll wind up with an early gyro overhaul).
Newer vacuum gyros tend to be more resilient than the old ones that birthed the "Don't let the gyros tumble" rule of thumb - they'll tolerate more extreme angles without tumbling - so there's less of a need to worry about damaging them in spin training.
(Solid-State gyros obviously won't suffer damage as they have no gimbals and bearings to beat up. They may however become "confused" and go offline if they sense something they're not designed for.)



As a note, I would not do spin training in a Cessna 172 (or any other typical trainer where spins are only authorized within the utility envelope) that hasn't had a recent physical weighing, unless your operating weight and balance range is squarely in the middle of the utility envelope.

A plane with many years of "computed" W&amp;B updates may in fact weigh 100lbs more (or, rarely, less) than the weight and balance sheets indicate, and the empty center of gravity could vary by an inch or more.

If you are going to be performing intentional spins it behooves you to ensure that you're actually operating within the envelope for which recovery has been tested.