1999 Camaros with the 3.8L V6 typically came with either a 4L60E automatic or a T5 5-speed manual transmission.
* 4L60E Automatic: This transmission is relatively common and *can* be used with various V8s, but it will likely require upgrades (torque converter, possibly internals) to handle the increased power and torque. You'll also need the appropriate bellhousing to mate the V8 to the 4L60E. Some V8s might need an adapter plate.
* T5 Manual: The T5 is *much* weaker and less likely to handle the power of a V8 without significant and likely impractical modifications. It's highly recommended to use a stronger transmission like a T56 (6-speed manual) or a different, more robust manual transmission designed for V8 applications.
Beyond the transmission, you'll also need to consider:
* Engine Mounts: You'll need engine mounts designed for the specific V8 you choose. The existing mounts won't work.
* Wiring Harness: The existing wiring harness won't be compatible. You'll either need to adapt it, splice in new wiring, or get a harness specific to your chosen V8.
* Exhaust System: You'll need a new exhaust system.
* Computer/ECU: The engine control unit (ECU) will need to be compatible with the V8. This may involve using a stand-alone ECU or finding a compatible factory ECU.
* Driveshaft: The driveshaft may need to be modified or replaced to accommodate the V8's different output.
In short: While swapping in a V8 is possible, it's a major undertaking requiring significant mechanical knowledge and a substantial budget. It's far from a simple "bolt-in" project. You'll need to research the specifics of the V8 you want to use and determine all the necessary components and modifications. Consulting with experienced Camaro mechanics or enthusiasts is highly recommended.
