Ron,
I don't know what Jerry has. It was probably for some type of Engine Management System retrofit and it does have 24 slots, but it won't be able to produce the signal that the LS1 PCM would need. See below:
The complete document from which this was taken can be downloaded here:
http://www.bowlingss.com/DownLoads/P...Holden_LS1.pdf
Jep