1.) I don't think it makes sense to recreate here that which is already well covered elsewhere; Billavista + the Jantz videos have gear setup covered and the Billavista bibles covering hydro steering, coilovers, brakes, and cooling are still the gold standard for these topics.
2.) I don't think "crowd-sourced" bibles will be very useful; by that I mean opening a thread where anyone can contribute. I think bibles work best when somebody (or a team) goes off, does the research, collects all the information, then presents it in a concise and orderly manner.
3.) Chit chat and other off-topic banter does not belong in tech threads.
4.) Some ideas for tech topics:
Carrier bearings - what is available, pros/cons of the various options, mounting, etc
Engine/transmission mounts - lots of broken transmission tail housings due to improper mounting. Cover theory, root cause for these tail housing breaks, pros/cons of rigid vs flexible mounts, show designs that work vs those that did not, etc.
Link suspension - Lets recreate the god of suspension? LOL. But in all seriousness I still have not seen a comprehensive and concise link suspension design "bible". Content would include definition of terms, describe the various configurations, i.e. double triangulated, single triangulated, wishbone, four link w/ track bar, three link w/ track bar, etc with graphics of each along with pros/cons and typical applications. Cover the math underlying roll center, roll steer, anti-squat, pinion angle. How does spring/shock angle impact suspension travel and frequency. How to accurately locate sprung mass center of gravity using scale measurements of the whole vehicle. Etc, etc. The recent videos posted by Busted Knuckle are really good but something that brings all the topics together with more depth would be great.
Bump stop and limit straps - Theory, market survey, placement tips. I see lots of bump stops that will work fine for pure bump but are basically useless for full flex.
LS motor crankcase ventilation - Differences between the various generations and RPO's. Problems with factory configurations for off road vehicles. Schematics of how to properly plumb catch can into crank case ventilation for various different RPC's
Vent tech covering diffs, t-cases, fuel cells, steering reservoirs - Theory. Survey what is available on the market, Pros/cons of various options. Design and placement of vents.
Rear-mounting battery(ies) - cabling, shut off switches, bus bars, etc