That's why you need to go to your rules meeting...
Its an oldschool rule from back in the day that I guess prevented people from running Chevettes with V8's or something, and mainly remained to keep people from shortening their chassis. All competitive chassis, metric, A and camero are 108 or longer stock. Hence the rule.
In practice, the rule has always been ignored at other tracks. I've seen Mustangs and a Thunderbird both with under 108 wheelbases run in the thunder class. Mustangs, T-birds, F-bodies and every other car under 108 wheelbase (except maybe a chevette) is a strut car. Struts don't work on the track anyhow as they are too floppy, meaning that they are not winning races, if you are not winning races no one cares or is measuring your wheelbase anyhow...
The issue is if the track removes the 108 rule for cars which are not a factor, then you will have some guy shortening his metric to a 100 wheelbase.
Call you track tech inspector directly. More than likely will not be an issue unless you become the first guy in oval racing to start winning outside of enduro with an f-body.
Good luck.
Linkback: https://www.canadianracingonline.com/smf/index.php?topic=20747.msg113133#msg113133
