There is another GM application which uses the 24x CKP signal and the 1x CMP(cam) signal. Its the 1998-2001 rpo L21 Vortec 454 which was used in MD/HD trucks as a replacement for the truck 366/427 engines. The L21 is the 1st BBC to run CNP(coil near plug-8 coils) and ETC(electronic throttle control). Basically its a L29 Vortec 454 (used in all 3/4 ton and 1 ton GM trucks from 96-00) with CNP and ETC. After MY2000 GM switched to the L18 8.1(496) GEN VII(GEN 7) BBC.
This crank reluctor wheel is the same wheel design that EFIConnection uses except it now fits the SBC crank snout.
Here are the GM P/N', this reluctor must be used with this CKP sensor.
Reluctor - 12552480 $19.10
crank sensor - 10456248 $71.77 as per GM parts direct
This reluctor wheel is much smaller than the LS1 wheels as its placed behind the balancer underneath a front timing chain cover.
The L21 used PCM's 16232148 and 16238212 which are the 1997-00 dual 80 pin connectored 512kb PCM's, the 411 PCM came after for the 01-02 Vette/Camaro/Firebird and a few 03 Vette applications.
Not sure if this might help or not, but its another (cheap) source of a 24x signal.
Page 11 of this
http://www.allworldautomotive.com/fe...Color_2011.pdflink has a pic. listed for a 1999-2000 BBC. On page 10 it shows the conventional Vortec 96-2000 Vortec 305/350 4x reluctor and the 1996-2000 Vortec V6 3x reluctor wheels. LS1(24x) and 8.1(24x) wheels are also listed with pics.
peace
Hog