Values taken from World of Warcraft Bestiary (which is much more complete for normals than it is for heroics, and since normals weren't nerfed nearly to the same extent, getting 2.3 values isn't a problem while for heroics you lose by default because you are guaranteed not to be getting pre-nerf values if the mob was ever changed). Bestiary isn't infallible but I would treat the values as exactly correct unless clear evidence disproves them. If values are missing from Bestiary (which is the case for roughly 5-10% of the mobs ignoring CoT instances), they are inferred based on other similar mobs (values achieved in this manner aren't usually specifically mentioned, but I tend to use round numbers so you can probably guess from looking at them).
Given that normals didn't have noteworthy changes to mechanics and spell values across the patches and CC tends to be "anything goes" rather than mob-specific immunity masks, they should already be "correct" in open source emulation, making damage values the only noteworthy missing detail.
Some differences between heroics and normals are listed but it's by no means a complete list.
Hellfire Ramparts
Watchkeeper Gargolmar: 603-838 - Normal doesn't have healing debuff
Omor the Unscarred: 1111-1543
Vazruden: 1086-1511
Nazdan: 1004-1397
Bonechewer Hungerer: 343-529
Bonechewer Ravener: 343-529
Bonechewer Destroyer: 619-955
Shattered Hand Warhound: 91-124
Bleeding Hollow Darkcaster: 446-706
Bleeding Hollow Archer: 343-503
Bonechewer Ripper: 382-529
Bleeding Hollow Scryer: 318-463
Bonechewer Beastmaster: 343-471
Hellfire Watcher: 284-400
Fiendish Hound: 144-199
Hellfire Sentry: 326-514
Blood Furnace
The Maker: 1255-1747
Broggok: 651-937
Keli'dan the Breaker: 805-1158
Laughing Skull Enforcer: 636-881
Shadowmoon Adept: 605-839
Hellfire Imp: 909-1259
Laughing Skull Rogue: 509-705
Shadowmoon Summoner: 443-707
Seductress: 545-801
Felhound Manastalker: 518-755
Laughing Skull Legionnaire: 636-881
Shadowmoon Warlock: 493-753
Shadowmoon Technician: 493-753
Laughging Skull Warden: 726-1011
Nascent Fel Orc: 217-326
Fel Orc Neophyte: 348-484
Felguard Brute: 637-882
Hellfire Familiar: 189-262
Felguard Annihilator: 826-1150
Shadowmoon Channeller: 275-383
Shattered Halls
Grand Warlock Netherkurse: 1406-1986
Warbringer O'mrogg: 1610-2277
Warchief Kargath Bladefist: 1388-1963
Shattered Hand Savage: 1127-1591
Shattered Hand Heathen: 1014-1431
Shattered Hand Legionnaire: 1262-1785
Shattered Hand Sentry: 1127-1591
Shadowmoon Darkcaster: 916-1330
Shadowmoon Acolyte: 916-1330
Shattered Hand Brawler: 1177-1664
Shattered Hand Reaver: 1127-1664
Shattered Hand Sharpshooter: 1127-1591
Fel Orc Convert: 435-634
Shattered Hand Houndmaster: 1177-1664
Rabid Warhound: 298-419
Creeping Ooze: 1127-1591
Creeping Oozeling: 121-171
Shattered Hand Assassin: 1010-1452
Shattered Hand Zealot: 242-341
Shattered Hand Archer: 967-1365
Shattered Hand Gladiator: 1177-1664
Shattered Hand Centurion: 1284-1815
Shattered Hand Champion: 1284-1815
Heathen Guard: 1014-1431
Reaver Guard: 1127-1664
Sharpshooter Guard: 1127-1591
Slave Pens
Mennu the Betrayer: 619-865
Rokmar the Crackler: 1240-1753 - No enrage
Quagmirran: 2289-3200
Bogstrok: 689-958
Greater Bogstrok: 689-958
Coilfang Slavehandler: 727-1065
Coilfang Champion: 747-1009
Wastewalker Slave: 150-200
Wastewalker Worker: 125-175
Coilfang Observer: 640-689
Coilfang Soothsayer: 523-752
Coilfang Enchantress: 640-889
Coilfang Ray: 687-960
Coilfang Defender: 724-1009
Coilfang Technician: 672-937
Coilfang Collaborator: 413-575
Coilfang Tempest: 700-900
Coilfang Scale-Healer: 640-937
Underbog
Hungarfen: 2005-2809
Ghaz'an: 962-1348
Swamplord Musek'ek: 1507-2109
Claw: 401-562
The Black Stalker: 1786-2500
Underbat: 689-1009
Underbog Shambler: 720-1055
Underbog Lurker: 861-1262
Bog Giant: 1307-1822
Underbog Frenzy: 647-874
Wrathfin Myrmidon: 762-1066
Wrathfin Sentry: 762-1066
Murkblood Tribesman: 724-1066
Wrathfin Warrior: 762-1066
Murkblood Oracle: 672-988
Murkblood Spearman: 672-988
Murkblood Healer: 672-988
Fen Ray: 687-960
Lykul Stinger: 687-960
Lykul Wasp: 652-909
Underbog Lord: 1905-2664
The Steamvault
Hydromancer Thespia: 1576-2227
Mekgineer Steamrigger: 2091-2957 - Leper gnomes spawn periodically in addition to every 25%
Warlord Kalithresh: 1699-2403
Coilfang Warrior: 1177-1664
Bog Overlord: 3282-4641
Coilfang Siren: 1092-1543
Coilfang Engineer: 1177-1664
Coilfang Oracle: 1092-1543
Tidal Surger: 1289-1821
Steam Surger: 351-496
Coilfang Myrmidon: 1177-1664
Coilfang Sorceress: 1092-1543
Coilfang Slavemaster: 1177-1664
Dreghood Slave: 706-999
Coilfang Water Elemental: 351-497
Coilfang Leper: 410-579
Steamrigger Mechanic: 570-700
Auchenai Crypts
Shirrak the Dead Watcher: 1136-1593
Exarch Maladaar: 2909-4111
Avatar of the Martyred: 1101-1548
Auchenai Soulpriest: 744-1093
Auchenai Vindicator: 744-1093
Phasing Soldier: 361-531
Phasing Cleric: 335-492
Phasing Sorcerer: 335-492
Auchenai Monk: 641-943
Unliving Soldier: 361-531
Phantasmal Possessor: 300-450
Unliving Stalker: 361-531
Unliving Cleric: 335-492
Unliving Sorcerer: 335-492
Angered Skeleton: 735-1032
Raging Skeleton: 735-1085
Auchenai Necromancer: 822-1212
Reanimated Bones: 231-341
Stolen Soul: 700-1000
Mana Tombs
Pandemonius: 735-1031
Tavarok: 735-1031 - Normal doesn't have Arcing Smash
Nexus-Prince Shaffar: 1136-1593
Shadow Lord Xiraxis: 1170-1640
Ethereal Crypt Raider: 858-1200
Ethereal Scavenger: 858-1200
Ethereal Sorcerer: 652-957
Arcane Fiend: 318-445
Ethereal Priest: 587-861
Nexus Terror: 953-1333
Mana Leech: 354-495
Ethereal Darkcaster: 685-957
Nexus Stalker: 858-1200
Ethereal Spellbinder: 513-755
Ethereal Theurgist: 575-805
Ethereal Wraith: 368-487
Ethereal Apprentice: 558-781
Ethereal Beacon: 186-260
Sethekk Halls
Darkweaver Syth: 1203-1694
Talon King Ikiss: 1755-2471 - Doesn't have slow
Sethekk Guard: 1080-1461
Sethekk Initiate: 1027-1445
Avian Darkhawk: 1014-1426
Time-Lost Controller: 714-1032
Sethekk Oracle: 714-1085
Syth Fire/Arcane/Shadow/Frost Elemental: 363-513 - Buffet spells are single target, unlike heroic
Sethekk Ravenguard: 860-1213
Time-Lost Scryer: 1534-1864
Cobalt Serpent: 1177-1657
Avian Ripper: 330-465
Sethekk Talon Lord: 898-1326
Sethekk Prophet: 750-1140
Sethekk Spirit: 2380-3270
Avian Warhawk: 1061-1496
Sethekk Shaman: 836-1178
Dark Vortex: 736-1034
Time-Lost Shadowmage: 786-1139
Shadow Labyrinth
Ambassadow Hellmaw: 2285-3232
Blackheart the Inciter: 1852-2619
Grandmaster Vorpil: 1413-1997
Murmur: 3257-4606
Cabal Deathsworn: 1127-1664
Cabal Acolyte: 1045-1473
Cabal Warlock: 1045-1473
Cabal Familiar: 284-412
Fel Guardhound: 471-664
Cabal Ritualist: 1045-1543
Fel Overseer: 1500-2000
Cabal Assassin: 1110-1569
Cabal Cultist: 1127-1664
Malicious Instructor: 1350-1900 - Doesn't have disarm
Cabal Shadow Priest: 1045-1543
Maiden of Discipline: 492-695
Tortured Skeleton: 362-512
Cabal Fanatic: 1177-1664
Cabal Zealot: 1095-1548
Cabal Executioner: 1436-2031
Cabal Spellbinder: 1092-1569
Cabal Summoner: 1092-1569
Summoned Cabal Deathsworn: 1127-1664
Summoned Cabal Acolyte: 1045-1473
Botanica
Commander Sarannis: 1523-2154 - Summons adds at 55% instead of on timer
High Botanist Freywinn: 1413-1997
Thorngrin the Tender: 2001-2826
Laj: 1960-2772
Warp Splinter: 1150-1650
Bloodwarder Protector: 1045-1543
Tempest-Forge Peacekeeper: 1450-2150
Bloodwarder Greenkeeper: 1045-1543
Bloodwarder Mender: 873-1329
Bloodwarder Falconer: 1177-1664
Bloodfalcon: 822-1160
Bloodwarder Steward: 1127-1664
Summoned Bloodwarder Reservist: 450-650
Summoned Bloodwarder Mender: 873-1329
Sunseeker Chemist: 1092-1543
Greater Frayer: 459-648
Sunseeker Botanist: 1092-1543
Sunseeker Researcher: 1092-1543
Frayer: 323-478
Sunseeker Geomancer: 1111-1569
Frayer Protector: 757-1071
Blue/Green/Red/White Seedling: 370-470
Sunseeker Channeller: 1006-1420
Sunseeker Herbalist: 1177-1664
Sunseeker Harvester: 1092-1543
Mutate Fleshlasher: 1177-1664
Nethervine Inciter: 1177-1664
Nethervine Reaper: 1177-1664
Nethervine Trickster: 1177-1664
Mutate Horror: 1200-1700
Mutate Fear-Shrieker: 1200-1700
Sunseeker Gene-Splicer: 1006-1420
Thorn Lasher: 353-500
Thorn Flayer: 353-500
Frayer Wildling: 353-500
Sapling: 353-500
Mechanar
Gatewatcher Gyro-Kill: 2091-2957
Gatewatcher Iron-Hand: 2091-2957
Mechano-Lord Capacitus: 2091-2957 - Normal mode has no polarities but has reflective shields. In addition, there's fewer nether bombs.
Nethermancer Sepethrea: 1576-2227
Raging Flames: 523-739
Pathaleon the Calculator: 848-1198
Tempest-Forge Patroller: 2200-3200
Bloodwarder Centurion: 1177-1664
Bloodwarder Physician: 1045-1543
Bloodwarder Slayer: 1177-1664
Sunseeker Netherbinder: 1006-1420
Arcane Servant: 351-497
Sunseeker Engineer: 1045-1473
Mechanar Tinkerer: 362-512
Mechanar Crusher: 1458-2062
Mechanar Driller: 1458-2062
Mechanar Wrecker: 1458-2062
Sunseeker Astromage: 1045-1473
Tempest-Forge Destroyer: 2600-3600
Nether Wraith: 351-497
Arcatratz
Zereketh the Unbound: 1455-2056
Dalliah the Doomsayer: 1777-2514
Wrath-Scryer Soccothrates: 2091-2957
Harbinger Skyriss: 969-1370
Arcatratz Defender: 1076-1591
Arcatratz Warder: 997-1473
Protean Horror: 400-600 None of the Protean mobs were in Bestiary. Inference made relative to Warder, and knowing Nightmare and Spawn were nerfed in heroic so I toned the numbers down a notch.
Protean Spawn: 300-400
Protean Nightmare: 1800-2400
Soul Devourer: 1894-2678
Entropic Eye: 1640-2317
Death Watcher: 1894-2678
Sightless Eye: 126-179
Arcatratz Sentinel: 1641-2321
Negaton Screamer: 1640-2317
Negaton Warp-Master: 2430-3436
Eredar Soul-Eater: 1757-2483
Eredar Deathbringer: 2636-3725
Unbound Devastator: 1894-2678
Spiteful Temptress: 1500-2150
Skulking Witch: 1894-2678
Ethereum Slayer: 1351-1910
Ethereum Life-Binder: 1254-1771
Ethereal Wave-Caster: 1254-1910
Gargantuan Abyssal: 2823-3993
Unchained Doombringer: 2567-3631
Sargeron Archer: 1582-2235
Sargeron Hellcaller: 1582-2235
Phase-Hunter: 2353-3327
Sulfuron Magma-Thrower: 1697-2398
Twilight Drakonaar: 2091-2957
Akkiris Lightning-Waker: 1576-2227
Blazing Trickster: 1406-1926
Blackwing Drakonaar: 2091-2957
Escape from Durnholde Keep
Epoch Hunter was the only listed mob in Bestiary. I'm not going to fill to all missing mobs with guessed values and no obvious counterparts to modify, but if someone wants numbers and doesn't want to use their brain, melee mobs most likely deal something in the order of 900-1300 damage, caster mobs 800-1000, non-elites 300-400 and bosses 1500-2000.
Lieutenant Drake:
Captain Skarloc:
Epoch Hunter: 1536-2166
Lordaeron Sentry:
Lordaeron Watchman:
Durnholde Mage:
Durnholde Rifleman:
Durnholde Sentry:
Durnholde Tracking Hound:
Durnholde Veteran:
Durnholde Warden:
Infinite Defiler: 855-1024
Infinite Saboteur: 855-1024
Infinite Slayer: 922-1299
Tarren Mill Guardsman:
Tarren Mill Lookout:
Tarren Mill Protector:
Opening of the Dark Portal
All the dragonkin values are missing. I'm not going to write down guessed values for them because they are each others' best points of comparison but I could fine one data point: Infinite Assassin is claimed to be doing 200-300 Sinister Strikes on cloth, suggesting his damage range is perhaps around 200-300 to 250-350. The caster mobs are presumably a tad below that.
Values taken from World of Warcraft Bestiary (which is much more complete for normals than it is for heroics, and since normals weren't nerfed nearly to the same extent, getting 2.3 values isn't a problem while for heroics you lose by default because you are guaranteed not to be getting pre-nerf values if the mob was ever changed). Bestiary isn't infallible but I would treat the values as exactly correct unless clear evidence disproves them. If values are missing from Bestiary (which is the case for roughly 5-10% of the mobs ignoring CoT instances), they are inferred based on other similar mobs (values achieved in this manner aren't usually specifically mentioned, but I tend to use round numbers so you can probably guess from looking at them).
Given that normals didn't have noteworthy changes to mechanics and spell values across the patches and CC tends to be "anything goes" rather than mob-specific immunity masks, they should already be "correct" in open source emulation, making damage values the only noteworthy missing detail.
Some differences between heroics and normals are listed but it's by no means a complete list.
Hellfire Ramparts
Blood Furnace
Shattered Halls
Slave Pens
Underbog
The Steamvault
Auchenai Crypts
Mana Tombs
Sethekk Halls
Shadow Labyrinth
Botanica
Mechanar
Arcatratz
Escape from Durnholde Keep
Epoch Hunter was the only listed mob in Bestiary. I'm not going to fill to all missing mobs with guessed values and no obvious counterparts to modify, but if someone wants numbers and doesn't want to use their brain, melee mobs most likely deal something in the order of 900-1300 damage, caster mobs 800-1000, non-elites 300-400 and bosses 1500-2000.
Opening of the Dark Portal
All the dragonkin values are missing. I'm not going to write down guessed values for them because they are each others' best points of comparison but I could fine one data point: Infinite Assassin is claimed to be doing 200-300 Sinister Strikes on cloth, suggesting his damage range is perhaps around 200-300 to 250-350. The caster mobs are presumably a tad below that.