Original specs

Where can I find original specs for a GM vehicle as it came from the factory? Specifically the 1988 GMC Jimmy Sierra 5.7. I looked up the casting numbers but can't find anyplace with complete orginal specs. I also can't find the cc # for the heads. Casting number 14102193 just shows up as 86-88 350 heads 1.94 1.5001. Is this a 76cc head? Thanks for the assist. ---Rich

BTW if you see this Tech, awsome explaination of compression. I totally got it after reading your post.

Thanks for the effort. It looks like I might have to try the *GASP!* Burette method. 64cc vs 76cc heads could make quite a compression difference. (I know 'cause I can calculate it now) :o