He is probably referring to the US Factory manuals which are used by Toyota technicians whenever servicing AE86's. They cover everything from body, chasis, electrical etc for both 4AGE and 4AC versions. As it is a US publication, I believe they only cover Trueno's & not Levins but how different can they be?
My understanding is that these manuals are no longer in print and most Toyota dealerships are too lazy to order them in even if you give them the part no.
I should be getting my hands on two copies hopefully in the next month so will probably be selling one but don't expect it to go cheap.
One just sold off Ebay for $123 US + $40 US postage.