How do I tell what kind of motor is in it so I can replace the full body throttle and sensor?

http://www.therangerstation.com/tech_library/VIN_Codes.html -- check the eight position in your vin. That is if its the original engine. Hope this helps

Why are you replacing such expensive parts? Throttle bodies don't fail unless damaged. If you don't know which engine you have, how do you know that you need a throttle body?

If it is a V-8, your choices are the 302 (5.0 litre) and 351 (5.8 litre). It takes a very experienced eye to tell the two apart. On the fan shroud or on the rad support, there should be an "Emissions Control" sticker that tells you the spark plug gap, timing base settings and vacuum line routing. That sticker will always tell you the engine size as installed at the factory. The engine size in in the small print at the top of the sticker. It is normally yellow, but if there is after market rust proofing applied, you may need varsol to clean it off to be able to read it. Normally the engine displacement is cast right into the upper intake manifold, too. Failing that, as noted above, the engine size is in the VIN for the truck.

351W

302 (5.0) this is older than 1989 but it's the 302. Click the pictures

Both those engines are older versions, with either a carburetor or a throttle body fuel injection system. Neither is gong to be much help here, I'm afraid. Unless you measure certain things, you can't tell the one from the other, especially in pictures, since the blocks are both Windsor blocks, just the 351 has a higher deck height. You may find that the throttle body is the same for both engines, by the way. It may not make a difference. As far as I know, the upper manifolds are the same between the two. Just the lower manifold is different to allow for the greater distance between the heads caused by that higher deck.

I need the bunching a of my f150