This is a old thread on forum64.de , i have translated it for you in english language. An old but very useful faq.

• C64 with Board Rev. 326298, 250407, 250425… (old C64 case):
• Rom 901227 (C64 Kernel) replace with 27C64 (8KB) Eprom. You need a special Adaptor 28 Pin Eprom to 24 pin Rom.

• C64C with Board 250469:
• Rom 251913 (C64 Basic & C64 Kernel) replace with 27C128 (16KB) Eprom. Without special Adaptor.

• 1541 with Board Rev. 154008, 154050, 250442, 250446 (old 1541 case):
• Rom 901229 (DOS Hi-Rom) replace with 27C64 (8KB) Eprom. You need a special Adaptor 28 Pin Eprom to 24 pin Rom.

• 1541-C with Board Rev. short motherboard (sometimes old 1541 Board in a new White Case):
• Rom 251968 (DOS Low-Rom & DOS High-Rom) replace with 27C128 (16KB) Eprom. Without special Adaptor.

• 1541-II:
• Rom 251968 (DOS Low-Rom & DOS High-Rom) replace with 27C128 (16KB) Eprom. Without special Adaptor.

• C128:
• Rom 251913 (C64 Basic & C64 Kernel) replace with 27C128 (16KB) Eprom. Without special Adaptor.

• 1570:
• Rom 315090 (1570 DOS Rom) replace with 27C256 (32KB) Eprom. Without special Adaptor.

• 1571:
• Rom 310654 (1571 DOS Rom) replace with 27C256 (32KB) Eprom. Without special Adaptor.

• C128-D Plastic Case:
• The same of C128 & 1571.

• C128-DCR Metal Case:
• Rom 318077 (C64 Basic, C64 Kernel, C128 Editor, Z80 Bios, C128 Kernel) replace with 27C256 (32KB) Eprom. Without special Adaptor.
• Rom 318047 (1571DCR DOS Rom) replace with 27C256 (32KB) Eprom. Without special Adaptor.

• 1581:
• Rom 318045 (1581 DOS Rom) replace with 27C256 (32KB) Eprom. Without special Adaptor.

source: forum64.de

download original roms: zimmers.net