I've seen these engine screwed up by so many "guru's" my blood pressure spikes whenever I hear the word...
TSRM = Toyota Service and Repair Manual. Chilton/Haynes are crap; They leave out a lot of important info, try to cram in info from various generations of the model even if they're completely different. The TSRM and TEWD (Toyota and Electronics Wiring Diagrams) are year specific, from Toyota and VERY detailed... Many novices do just fine as long as they follow it closely. There's an online version of the TSRM and TEWD for a '90 model... most of it is the same; Enough for rebuilding the block anyway.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/