You can bolt TBI onto almost any motor. The main thing is youll need a Crankshaft position sensor, a o2 sensor and a map sensor. LT1 has a good idea in buying a pre-assembled EFI motor if you dont mind having a standard motor. Personally, I would go the Painless wiring/programmable computer setup with a Big Block considering that the 65/66s had bottomless engine bays, but thats only one way to go.