Chip Programming for engine swaps or performance modding
Most engine conversions require making changes to the Engine Control Module (ECM) in order to make the swap perform perfectly, or even work at all. The changes may be as minor as turning off one or two error codes or disabling anti-theft systems, or could be major changes such as completely re-tuning the fuel delivery and spark timing for a highly modified engine. It's also not uncommon to take an ECM that was designed for a particular engine and use it to run a different engine. I won't get into how to edit any specific ECM, there are other sources for that information. I will try to give you a basic understanding of how it is done.
Most GM ECMs used until 1995 have an Erasable Programmable Read Only Memory (EPROM) that stores data about the particular engine it controls. Some EPROMs also contain information specific to the transmission and the car. The EPROM is often referred to as the "chip". The chip is sometimes located in a removable carrier called a MemCal or Calpack. To edit the chip, you will need a few things. You'll need a PC or laptop computer, since you are reading this I'll assume you already have one. You will need an EPROM programmer or device programmer that is compatible with the EPROM in your ECM. You will need an EPROM eraser, most stock GM EPROMs are erasable and reusable. You may also want to have a few 'spare' chips to work with. And lastly, you will need editing software that supports the ECM you are using. It takes some time to learn how to use these tools, and it takes some money to get started. Unless you can make use of it on several projects, you'd be better off just finding someone who can do it for you.
I use the following tools for all of my editing.