[Cdncarnut]

From the 2016 Rule Book, in the in Section 10 Stock Cars

IGNITION, Automatic
Two-step permitted. Two-step must be foot-activated through
brake pedal, clutch pedal, or pressure switch. Hand release
prohibited. All wiring associated with the ignition system must be
fully visible, labeled, and traceable. See General Regulations 8:3.

And, from the General Regulations

.
8:3 IGNITION
Each car in competition must have a positive-action on/off switch,
capable of de-energizing the entire ignition system, in good
working order, located within easy reach of the driver.
“Momentary contact” switch prohibited. Magneto “kill button”-type
switches are prohibited.
All ignition systems and/or components wiring harnesses and
attachments must utilize those supplied by the ignition system
manufacturer. The wiring harness must be used in an unaltered
manner consistent with the manufacturer’s installation and
instruction books. All wiring associated with the ignition system
must be fully visible, labeled, and traceable.
All removable or pin-type timing devices are prohibited. Two-steps
or other rev limiters that are adjustable by thumbwheel, replaceable
chips, and the like may not be within the driver’s reach and will
preferably be located outside the driver compartment.
The use of any programmable multi-point rev limiter and/or a
rate-of-acceleration rpm limiter, either by themselves (e.g., MSD
7561 , MSD 7761 ) or integrated into the ignition system (e.g.,
MSD 7531 ), is prohibited in NHRA competition.

From all I read there, you are good to go with the micro switch on the shifter.