Sorry but Any FSM is Not "the best" manual for most DIY or even many "Pros" because can't read them. That's including most GM dealer service dept. That's ignoring big errors and more because "Authors" copy/past a lot of data from other models w/o checking the data is right. Many TSB's fixes some errors but often errors are never fix.
Example: read http://www.fiero.nl/forum/F.../HTML/138175.html#p1
In short O & P bulbs are never listed in any FSM or TSB.
I've read Many GM FSM and others For Decades and still have to deal how hard they are to read them.
FSM is good but reading it is hard to very hard to many and impossible to others. Again, even Dealer service people often won't read them because too hard and takes too much time to decipher many pages.
Can get one but don't think will have all the answers in easy to read text.
AllDataDIY gets data from GM and have same errors and most wont bother w/ TSB database there because of very poorly written. Worse is hard to find many things on the site because AD putts data in weird places so don't expect looking in one spot.
Crap Haynes and Chilton books have big problems too and often missing important data.
Worse paraphrase etc FSM to get around GM © to publish the books often have more errors because source data is wrong to start with.
Example: Haynes has 88 engine balancer but ignore 700 series TBI or DIS and even says L4 doesn't use a MAT sensor makes it worthless for 87-88 L4.
Is a big part of Why I wrote my Cave like My Cave has 700 TBI and DIS plus has sort story how to read FSM electrical data. Other big part was to be a FAQ for PFF before CP caved and made "FAQs & HowTos" section years later.
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
The Ogre's Fiero Cave