Best engine manual for a '71 400?
 

I mistakenly thought the Firebird Assembly Manual sold by the parts houses would have detailed diagrams and drawings of the motor itself. (It's basically everything but that.)

Is there a manual with diagrams, specs and part numbers for a '71 YS-block 400, casting code 481988? The closest thing I can find is a CD-ROM "1971 Pontiac Factory Repair Shop & Service Manual & Fisher Body Manual - GTO, Grand Prix, T37, GT37, Firebird & Trans Am." This includes the S-6804 Chassis Manual which supposedly has engine-mechanical info. Has anyone used this? Is the reprint readable and how detailed is the engine info? Thanks --

Any 1971 to 1975 (and possibly later) Illustrated Master Parts Catalog (MPC) Emphasis on the illustrated. The MPC was issued yearly and usually would cover 10 + years prior.

The service manual will provide the specs and diagrams