This conversion will require a lot of parts in order to work properly. You'll need to find the same engine at a junk yard with a throttle-body injection (TBI), since basically TBI is a glorified, electronically-controlled carburetor. However, you'll of course need to scavenge the computer guts as well as the air intake (with appropriate sensors) and intake manifold (as the throttle-body will not directly bolt to the old one), the EGR valve and vacuum lines, and you'll need the exhaust manifold with a port for an oxygen sensor. Depending on the year (the newer the engine, the more complex the system) you may also need to figure out whether you need crank positioning sensors and such. It depends largely on what the computer needs to know in order to calculate the best air/fuel mixture for the current RPMs and load. Sometimes you can skate by without certain things as the computer may be smart enough to plug default values into non-existent sensor readings, but it could also keep the engine from starting all together, or cause rough idles, stalling, and so forth. I can't get into specifics here, so a search will do you some good, but I can tell you this isn't as easy as dropping a TBI where the carb used to be. Be prepared to tear that engine down as it certainly has not been designed for any sensors whatsoever.