Understanding -iLevels as Opposed to Tiers in Modern World of Warcraft Prior to Cataclysm

iLevels.

5 man Heroics: 200
5 man Heroic Trial of Champion: 219
10 man Naxx: 200 (KT drops 213)
25 man Naxx: 213 (KT drops 226)
10 man Malygos: 213
25 Malygos: 226
10 Sartharion: 200 (2 Drakes Up drops additional 213)
25 Sartharion: 213 (2 Drakes Up drops additional 226)
10 Ulduar: 219 (hard mode goes up to 226)
25 Ulduar: 226 (some weapons are 232, hard mode goes up to 239)
10 Trial of Crusader: 232
10 Heroic Trial of Crusader: 245
25 Trial of Crusader: 245
25 Heroic Trial of Crusader: 258

Examples - Early Tiers:

Not worrying about early tiers of toon level 10-20.
Modern Tiers (iLevels)

Toon level 10-21 can wear approximately iLevel 19-25 as available in Public AH

Old Tier .0 - required any level - probably late 50's or 60 but:could be blue or purple (rare or epic) many levels of armor dep. on quishy to plate iLevel probably about 46

Modern Tiers (iLevels)

Toon level 10-20 could wear approximately iLevel 19-25 as available in Public AH

Toon level 20-30 could wear appoximately iLevel 25-40 as available in public AH

Toon level 30-40 (not exact) could wear approximately iLevel 40-50 as available in public AH

Toon level 40-50 (not exact) could wear approximately iLevel 45-60 as available in public AH

Tier 1: example - Arcanist Belt (clothie/squishy)
65 Armor
Epic gear for a level 60 in BC days
Item Level late 50's in BC days
Toon Level - 55-65
Modern level late 50's to mid 60's

MODERN - AH -
Tier 1 Armor level varies by type (squishy to plate)
Toon level 60-65
Blue to Epic gear availble for ilevel 60+67

Tier 2:
Example of T2 gear: Judgement Crown
Requires Level 60? in old (BC and pre-BC days)
Original Item Level 76
Modern: toon level 65-69
Modern iLevel 103-130

example:
Judgement Breastplate (paladin/mail or plate)
978 Armor
Plate
Requires Level 60
Item Level 76
Modern: toon level 65-69
Modern iLevel 103-130

Example Tier 3 - leather:

Bonescythe Legplates
253 Armor
Requires Level 60
Item Level 88
MODERN: toon level 65-69
Modern iLevel 103-130

Stand to reason that:

Tier 4 would have been range of armor, etc. due to type
Tier 4 would have been character level 45-75
Tier 4 would have been appoximate iLevel 96-99

Example old T4: Justicar Armor (plate)
6136 Armor
Some of the first socketed gear.

MODERN: toon level 65-70
iLevel 100-130-ish

Stand to reason that:

Old Tier 5 would be range of armor, etc. due to type
Old Tier 5 would be character level 55-75
Old Tier 5 would be appoximate iLevel 96-110

MODERN toon level 70-75, iLevel - 70-200

Old Tier 6-8 would be range of armor, etc. due to type
Old Tier 6-8 would be character level 55-80 late Outland

and early Northrend starter
Old Tier 6-8 would be appoximate iLevel 96-110

MODERN: toon level 75-80 basic - iLevel - 75-200

THIS IS WHERE IT GET'S MORE IMPORTANT FOR THOSE 78-80+ PLAYING WRATH PRIOR TO CATACLYSM:

After Wrath of the Lich King:

Tier 7-7.25 is - ilevel 200 epic
Would be appropriate for level 70-80 in starter stage
Toon level 80 (plus?) and iLevel 200 plus for starters like Nexxus and UK

Tier 7.5 is ilevel 213-218 - some still available in AH, some only in instances.
Would be intermediate gear for level 71-80 in medium stages at low tier 8-ish is ilevel 218-225 - some still available in AH, some only in instances.

Would be intermediate to low maxiumum instance gear for level 80 in Northrend, mid tier 8 is iLevel 226 and approxiate for low to mid instance gear in Northrend (example heroic UK, Nax, to regular regular 25 man Ulduar)

Tier 8.5-ish might be iLevel 225-late 230's and should allow you do to almost any Northrend instance, but be more careful in the most high heroics and high number-raids.

Last tier available as of late 2009- iLevel 240-246 gear in 2009 (as far as author is aware) so should technically allow you to do any end-game content in late 2009.

Tier 9 is the armor set associated with the Crusaders' Coliseum, released in patch 3.2. Awarded by the Argent Crusade, tier 9 is designed to ready players for the crusade's eventual march on Icecrown Citadel to take on the Lich King.

Notes:

____ of Conquest: item level 232 (Purchasable through

[Emblems of Triumph])
____ of Triumph: item level 245 (10-player Heroic mode

(Tribute Chest only) and 25-player mode Purchasable

through [Emblems of Triumph] with 1 drop)
____ of Triumph: item level 258 (25-player Heroic mode

(Tribute Chest only))
No matter which level of tier 9 is worn, all pieces count towards the same set bonuses, much like in earlier tiers of gear. Each faction has their own flavor of the items, they are functionally identical, but have different artwork and names.

Usually: Item level 232 pieces are bought with [Emblems of Triumph]. Item level 245 pieces require 1.5x Emblems of Triumph as the Item level 232 pieces require and they also require in addition to the emblems, a [Trophy of the Crusade].

So, there are your basics, probably through at least the end of 2009. iLevels CAN be understood, but trying to get the info from multiple sites can be daunting! I hope this helps.