Yes, old thread. BUT this thread keeps turning up in my searches for installing cruise control in my S14 SR. Figure I can provide a small update. My apologies if this is already common knowledge.
The P11 (99-02) G20 throttle body bolts up, and the throttle position sensor can be swapped over without an modifications. The S14 TPS wiring also plugs into the top connector if you don't want to switch sensors around. The bottom one is for auto trans WOT/Closed switches, leave unplugged.
Here are some pics of a 99 G20 throttle body and my S14 SR20DET throttle body:
P11 left, S14 Right.
S14 left, P11 right. Essentially identical.
P11 left, S14 right. TPS sensors. Use top plug on P11 for a true PnP affair.
Cleaned up P11 TB with S14 TPS installed. Need to fabricate a cable bracket since nothing really lines up anymore. Too bad the OPs pics don't work.
Installed. On S14 the left coolant line comes strait out, but there's enough hose to connect to P11. It has one vacuum port, the S14 TB has 2, but one is plugged anyway.
Hope this helps future searchers.