I'd get an 05+ LQ4 if you can. The 05 and up motors have the stronger LS2 style rods and timing chain. If not, any 01+ LQ4 would be fine as long as it wasn't abused.

Quote Originally Posted by jtaliaferro View Post
99-02 is DBC which will be compatible with your current setup.

03-0x will DBW which you will have to purchase the Tac module and pedal for DBW

05-0x you would have to make provisions for Efans since those motors will not have a mechanical fan

If it was me, I would reuse my old harness and throtle body (if going with 03 and newer) and it will be easy as cake
None of this matters....he can reuse his original accessories, throttle body, intake manifold, etc and not have compatibility issues.