The previous owner of my truck had bought every type of service manual for the 1987 model year, from the dealer. I remember seeing those 3-digit codes translated in there, but I am not sure for what years they cover.
'87 Jimmy 4X4 2.8L [img]/wwwthreads_images/icons/crazy.gif[/img]
there is a place on the s10-4x4.com websight that will do it for you. Here is the addy just copy and past it. http://S10-4X4.COM/RPO/
<font color=blue>Jeff Henderson
Asst Webmaster @ s10-4x4.com
The best s10 4x4 websight is http://www.s10-4x4.com
My home http://www.geocities.com/diesel22_us</font color=blue>[img]/wwwthreads_images/icons/cool.gif[/img]