I would like to give a HUGE thanks to the team behind this. Go check out everything they've done here.
Gen 1 Stats
For those who don't know, the data for the Pokemon Gold Demo was leaked. With that data, the preliminary stat changes for changing a Pokemon's Special stat into Special Attack and Special Defense stats was leaked.
The above spreadsheet shows a Pokemon's preliminary Special Attack and Special Defense stats, their finalized Special Attack and Special Defense stats, and the net gain or loss from the demo to the final release (if any). Thanks Crystal_ for collecting this.
Here are some notable stat changes. Anything in red is considered a nerf, and green a benefit. The format goes as
	
	
		
			
		
		
	
	
		
	Snorlax
		
	Cloyster
		
	Vaporeon
		
	Exeggutor
		
	Nidoking
		
	Rhydon
		
	Jolteon
		
	Jynx
		
	Golem
		
	Alakazam
		
	Nidoqueen
		
	
Early Gen 2 Pokemon information
	
	
		
			
		
	
	
	
		
			
		
	Bulbasaur
		
	Ivysaur
		
	Venusaur
		
	Charmander
		
	Charmeleon
		
	Charizard
		
	Squirtle
		
	Wartortle
		
	Blastoise
		
	Caterpie
		
	Metapod
		
	Butterfree
		
	Weedle
		
	Kakuna
		
	Beedrill
		
	Pidgey
		
	Pidgeotto
		
	Pidgeot
		
	Rattata
		
	Raticate
		
	Spearow
		
	Fearow
		
	Ekans
		
	Arbok
		
	Pikachu
		
	Raichu
		
	Sandshrew
		
	Sandslash
		
	Nidoran♀
		
	Nidorina
		
	Nidoqueen
		
	Nidoran♂
		
	Nidorino
		
	Nidoking
		
	Clefairy
		
	Clefable
		
	Vulpix
		
	Ninetales
		
	Jigglypuff
		
	Wigglytuff
		
	Zubat
		
	Golbat
		
	Oddish
		
	Gloom
		
	Vileplume
		
	Paras
		
	Parasect
		
	Venonat
		
	Venomoth
		
	Diglett
		
	Dugtrio
		
	Meowth
		
	Persian
		
	Psyduck
		
	Golduck
		
	Mankey
		
	Primeape
		
	Growlithe
		
	Arcanine
		
	Poliwag
		
	Poliwhirl
		
	Poliwrath
		
	Abra
		
	Kadabra
		
	Alakazam
		
	Machop
		
	Machoke
		
	Machamp
		
	Bellsprout
		
	Weepinbell
		
	Victreebel
		
	Tentacool
		
	Tentacruel
		
	Geodude
		
	Graveler
		
	Golem
		
	Ponyta
		
	Rapidash
		
	Slowpoke
		
	Slowbro
		
	Magnemite
		
	Magneton
		
	Farfetch'd
		
	Doduo
		
	Dodrio
		
	Seel
		
	Dewgong
		
	Grimer
		
	Muk
		
	Shellder
		
	Cloyster
		
	Gastly
		
	Haunter
		
	Gengar
		
	Onix
		
	Drowzee
		
	Hypno
		
	Krabby
		
	Kingler
		
	Voltorb
		
	Electrode
		
	Exeggcute
		
	Exeggutor
		
	Cubone
		
	Marowak
		
	Hitmonlee
		
	Hitmonchan
		
	Lickitung
		
	Koffing
		
	Weezing
		
	Rhyhorn
		
	Rhydon
		
	Chansey
		
	Tangela
		
	Kangaskhan
		
	Horsea
		
	Seadra
		
	Goldeen
		
	Seaking
		
	Staryu
		
	Starmie
		
	Mr. Mime
		
	Scyther
		
	Jynx
		
	Electabuzz
		
	Magmar
		
	Pinsir
		
	Tauros
		
	Magikarp
		
	Gyarados
		
	Lapras
		
	Ditto
		
	Eevee
		
	Vaporeon
		
	Jolteon
		
	Flareon
		
	Porygon
		
	Omanyte
		
	Omastar
		
	Kabuto
		
	Kabutops
		
	Aerodactyl
		
	Snorlax
		
	Articuno
		
	Zapdos
		
	Moltres
		
	Dratini
		
	Dragonair
		
	Dragonite
		
	Mewtwo
		
	Mew
		
	Leef
		
	Blossomole
		
	Blossomite
		
	Flambear
		
	Volbear
		
	Dynabear
		
	Cruz
		
	Aqua
		
	Aquaria
		
	Hoothoot
		
	Hoohoo (Noctowl)
		
	Baaspark (Mareep)
		
	Flaaffy
		
	Ampharos
		
	Trifox
		
	Tangel
		
	Gelanla (Tangrowth)
		
	Rayleep (Mantine)
		
	Babul (Qwilfish)
		
	Numpuff
		
	Pichu
		
	Cleffa
		
	Igglybuff
		
	Lanceffish (Quagsire)
		
	Natu
		
	Xatu
		
	Golppy
		
	Marill
		
	Sunmola1
		
	Anchorage
		
	Grotess
		
	Ecksing (Crobat)
		
	Para
		
	Spidette (Spinarak)
		
	Tuhedd (Ariados)
		
	Armorawk (Skarmory)
		
	Animon
		
	Chiks
		
	Sunnee (Sunflora)
		
	Trunpet (Phanpy)
		
	Donphan
		
	Twinz
		
	Girafarig
		
	Paintern (Smeargle)
		
	Meowsy
		
	Rinring
		
	Bellboyant
		
	Politoed
		
	Slowking
Unown
		
	Ledyba
		
	Tripstar (Ledian)
		
	Minicorn
		
	Espeon
		
	Umbreon
		
	Turbann
		
	Grimey
		
	Remoraid
		
	Octillery
		
	Gohng (Tyrogue)
		
	Hitmontop
		
	Puddi
		
	Lefmew (Hoppip)
		
	Dandemew (Skiploom)
		
	Cottomew (Jumpluff)
		
	Ballerine (Mime Jr.)
		
	Lipp (Smoochum)
		
	Elebabee (Elekid)
		
	Magby
		
	Bellossom
		
	Belmitt
		
	Miltank
		
	Bomseel
		
	Ghift (Delibird)
		
	Tigrette
		
	Electiger
		
	Madame
		
	Kurstraw
		
	Pangshi
		
	Murkrow
		
	Happi (Blissey)
		
	Scizors (Scizor)
		
	Plux
		
	Devull (Houndour)
		
	Houndoom
		
	Wolfman
		
	Warwolf
		
	Porygon2
		
	Likk (Lickilicky)
		
	Steelix
		
	Kingdra
		
	Rai (Raikou)
		
	En (Entei)
		
	Sui (Suicune)
		
	Sneasel
		
	Ho-Oh
		
	Togepi
		
	Snubbull
		
	Tael (Aipom)
		
	Leafeo (Leafeon)
		
	
				
			Gen 1 Stats
For those who don't know, the data for the Pokemon Gold Demo was leaked. With that data, the preliminary stat changes for changing a Pokemon's Special stat into Special Attack and Special Defense stats was leaked.
The above spreadsheet shows a Pokemon's preliminary Special Attack and Special Defense stats, their finalized Special Attack and Special Defense stats, and the net gain or loss from the demo to the final release (if any). Thanks Crystal_ for collecting this.
Here are some notable stat changes. Anything in red is considered a nerf, and green a benefit. The format goes as
demo stat -> final stat (net gain/loss):
SpD: 100 -> 110 (+10)
SpD: 70 -> 45 (-25)
SpA: 70 -> 110 (+40)
SpD: 110 -> 95 (-15)
SpD: 65 -> 75 (+10)
SpA: 55 -> 85 (+30)
SpD: 70 -> 45 (-25)
SpA: 70 -> 110 (+40)
SpD: 110 -> 95 (-15)
SpA: 95 -> 115 (+20)
SpD: 80 -> 95 (+15)
SpD: 80 -> 65 (-15)
SpD: 85 -> 95 (+10)
SpA: 55 -> 75 (+20)
SpD: 75 -> 85 (+10)
Early Gen 2 Pokemon information
- Magnemite
- Pure Electric typing
 
 - Magneton
- Pure Electric typing
 
 - Grass starter's original names were Leef, Blossomole, and Blossomite
 - Fire starter's original names were Flambear, Volbear, and Dynabear
 - Water starter's original names were Cruz, Aqua, and Aquaria
- Believed to have influenced Popplio's evolution line
 
 - Hoothoot
- Located at dex #161
 - Pure Flying typing
 - Pre-evolution of Hoohoo (Alleged), evolution data missing
 
 - Hoohoo
- Located at dex #162
 - Pure Flying typing
 - Early Noctowl
 
 - Baaspark
- Located at dex #163
 - Pure Electric typing
 - Early Mareep
 
 - Trifox
- Located at dex #166
 - Pure Fire typing
 - Pre-evolution of Vulpix, evolves at level 13
 
 - Tangel
- Located at dex #167
 - Pure Grass typing
 - Pre-evolution of Tangela, evolves at level 22
 
 - Tangela
- Pre-evolution of Gelanla, evolves at level 44
 
 - Gelanla
- Located at dex #168
 - Pure Grass typing
 - Early Tangrowth
 
 - Rayleep
- Located at dex #169
 - Water / Flying typing
 - Early Mantine
 
 - Babul
- Located at dex #170
 - Pure Water typing
 - Pre-evolution of Numpuff, evolves at level 18
 - Early Qwilfish
 
 - Numpuff
- Located at dex #171
 - Pure Water typing
 
 - Lanceffish
- Located at dex #175
 - Pure Water typing
 - Early Quagsire
 
 - Golppy
- Located at dex #178
 - Pure Water typing
 - Pre-evolution of Goldeen, evolves at level 16
 
 - Natu
- Evolves into Xatu via Heart Stone
 
 - Sunmola1
- Located at dex #180
 - Pure Water typing
 - Pre-evolution of Anchorage, evolves at level 19
 
 - Anchorage
- Located at dex #181
 - Water / Steel typing
 - Pre-evolution of Grotess, evolves at level 38
 - Believed to have influenced Huntail or Sharpedo
 
 - Grotess
- Located at dex #182
 - Water / Steel typing
 - Believed to have influenced Gorebyss, Huntail, or Lanturn
 
 - Golbat
- Pre-evolution of Ecksing, evolves at level 44
 
 - Ecksing
- Located at dex #183
 - Poison / Flying typing
 - Early Crobat
 
 - Para
- Located at dex #184
 - Pure Bug typing
 - Pre-evolution of Paras, evolves at level 12
 
 - Spidette
- Located at dex #185
 - Bug / Poison typing
 - Pre-evolution of Tuhedd, evolves at level 23
 - Early Spinarak
 
 - Tuhedd
- Located at dex #186
 - Bug / Poison typing
 - Name is similar to Zweilous's Japanese name (Dihead)
 - Early Ariados
 
 - Armorawk
- Located at dex #187
 - Flying / Steel typing (Same types, just flipped)
 - Original sprite almost identical to final
 - Early Skarmory
 
 - Ditto
- Pre-evolution of Animon, evolves via Metal Coat
 
 - Animon
- Located at dex #188
 - Pure Normal typing
 - Evolved form of Ditto
 - Potentially influenced the creation of Metal Powder
 
 - Chiks
- Located at dex #189
 - Normal / Flying typing
 - Pre-evolution of Douo, evolves at level 16
 
 - Sunnee
- Located at dex #190
 - Grass / Psychic typing
 - Early Sunflora
 
 - Trunpet
- Located at dex #191
 - Pure Ground typing
 - Pre-evolution of Donphan, evolves at level 33
 - Early Phanpy
 
 - Twinz
- Located at dex #193
 - Dark / Normal typing
 - Pre-evolution of Girafarig, evolves at level 29
 
 - Girafarig
- Dark / Normal typing
 
 - Paintern
- Located at dex #195
 - Early Smeargle
 
 - Meowsy
- Located at dex #196
 - Pure Normal typing
 - Pre-evolution of Meowth, evolves at level 14
 
 - Rinring
- Located at dex #197
 - Pure Dark typing
 - Female only
 - Pre-evolution of Bellboyant, evolves at level 28
 
 - Bellboyant
- Located at dex #198
 - Pure Dark typing
 
 - Politoed
- Located at dex #199
 - Evolves from Poliwhirl via Heart Stone
 
 - Unown
- Located at dex #201
 - Pure Normal typing
 
 - Tripstar
- Located at dex #203
 - Early Ledian
 
 - Minicorn
- Located at dex #204
 - Pure Normal typing
 - Pre-evolution of Ponyta, evolves at level 20
 
 - Eevee
- Pre-evolution of Espeon, evolves via Heart Stone
 - Pre-evolution of Umbreon, evolves via Poison Stone
 - Pre-evolution of Leafeo, evolves via Leaf Stone
 
 - Umbreon
- Located at dex #206
 - Pure Poison typing
 
 - Turbann
- Located at dex #207
 - Pure Water typing
 - Slowking's shell/crown, no correlation to Shellder or Slowpoke lines
 
 - Grimey
- Located at dex #208
 - Pure Poison typing
 - Pre-evolution of Grimer, evolves at level 19
 
 - Remoraid
- Located at dex #209
 - Pre-evolution of Octillery, evolves at level 34
 
 - Gohng
- Located at dex #211
 - Pre-evolution of Hitmonchan, Hitmonlee, and Hitmontop, evolves at level 15
 - Early Tyrogue
 
 - Puddi
- Located at dex #213
 - Pre-evolution of Growlithe, evolves at level 13
 
 - Lefmew
- Located at dex #214
 - Pre-evolution of Skiploom, evolution data missing
 - Early Hoppip
 
 - Dandemew
- Located at dex #215
 - Pre-evolution of Jumpluff, evolves at level 40
 - Early Skiploom
 
 - Cottomew
- Located at dex #216
 - Early Jumpluff
 
 - Ballerine
- Located at dex #217
 - Pure Normal typing
 - Pre-evolution of Mr. Mime, evolves at level 15
 - Early Mime Jr.
 
 - Lipp
- Located at dex #218
 - Pre-evolution of Jynx, evolves at level 15
 - Early Smoochum
 
 - Elebabee
- Located at dex #219
 - Pre-evolution of Electabuzz, evolves at level 15
 - Early Elekid
 
 - Magby
- Located at dex #220
 - Pre-evolution of Magmar, evolves at level 15
 
 - Gloom
- Pre-evolution of Belossom, evolves via Poison Stone
 
 - Belossom
- Located at dex #221
 - Grass / Poison typing
 
 - Weepinbell
- Pre-evolution of Bellmit, evolves via Poison Stone
 
 - Bellmitt
- Located at dex #222
 - Grass / Poison typing
 
 - Bomseel
- Located at dex #224
 - Water / Fire typing
 
 - Ghift
- Located at dex #225
 - Water / Ice typing
 - Early Delibird
 
 - Tigrette
- Located at dex #226
 - Pure Electric typing
 - Pre-evolution of Electiger, evolves at level 35
 
 - Electiger
- Located at dex #227
 - Pure Electric typing
 - Similar cry to Dragonair's
 
 - Farfetch'd
- Pre-evolution of Madame, evolves at level 24
 
 - Madame
- Located at dex #228
 - Normal / Flying typing
 
 - Kurstraw
- Located at dex #229
 - Pure Ghost typing
 - Pre-evolution of Pangshi, evolves at level 1
 
 - Pangshi
- Located at dex #230
 - Pure Ghost typing
 
 - Chansey
- Pre-evolution of Happi, evolves at level 45
 
 - Happi
- Located at dex #232
 - Pure Normal typing
 - Early Blissey
 
 - Scyther
- Pre-evolution of Scizors, evolves at level 31
 
 - Scizors
- Located at dex #233
 - Bug / Flying typing
 - Early Scizor
 
 - Pinsir
- Pre-evolution of Plucks, evolves at level 42
 
 - Plucks
- Located at dex #234
 - Pure Bug typing
 
 - Devull
- Located at dex #235
 - Pure Fire typing
 - Pre-evolution of Houndoom, evolves at level 35
 - Early Houndour
 
 - Houndoom
- Located at dex #236
 - Pure Fire typing
 
 - Wolfman
- Located at dex #237
 - Pure Ice typing
 - Pre-evolution of Warwolf, evolves at level 25
 - Potentially early Snover or Swinub
 
 - Warwolf
- Located at dex #238
 - Pure Ice typing
 - Potentially early Abomasnow or Piloswine
 
 - Lickitung
- Pre-evolution of Likk, evolves at level 32
 
 - Likk
- Located at dex #240
 - Pure Normal typing
 - Early Lickilicky
 
 - Onix
- Pre-evolution of Steelix, evolves at level 38
 
 - Rai
- Located at dex #243
 - Early Raikou
 
 - En
- Located at dex #244
 - Early Entei
 
 - Sui
- Located at dex #245
 - Early Suicune
 
 - Sneasel
- Located at dex #246
 - Pure Dark typing
 
 - Ho-Oh
- Located at dex #247
 - Pure Flying typing
 
 - Togepi
- Located at dex #248
 - No Evolution
 
 - Snubbull
- Located at dex #249
 - Pure Psychic typing
 - No evolution
 - Female only
 
 - Tael
- Located at dex #250
 - Early Aipom
 
 - Leafeo
- Located at dex #251
 - Pure Grass typing
 - Early Leafeon
 
 
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
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