He runs SCCA street touring right?
per SCCA manual :
https://dk1xgl0d43mu1.cloudfront.ne...ion-14-street-touring-category.pdf?1484692402
the only thing i could find for radiator/engine cooling is seccion 14.10 PART L
Engine cooling radiators may be replaced with alternate parts subject to
the following restrictions:
1. Radiator core dimensions (width, height, thickness)
cannot be smaller
than the standard part.
2. Radiator
must mount to OE radiator mounts
3.Fluid capacity and dry weight of the radiator
must be no less than that
of the standard part. Installation of an alternate radiator may serve no
other purpose (e.g., to allow a cold air intake passage).
i think he is in the clear imo