Well, here's the deal: I did tons of research. I consider myself very mechanically inclined. I've only been to a mechanic 3 times in my life. Usually due to lack of time or tools. At any rate, I too contemplated the 3F head/injection option at first. WHY? well, until very recently, I would consider myself a Landcruiser Purist. I would have never have put a WEBER, much less a GM TBI!!! In the past I'd come to believe in Genuine Toyota ONLY. NEVER found any aftermarket parts that weren't junk. Regret almost every aftermarket purchase I ever made (mostly from SOR and CCOT...the latter being NOTORIOUS for AFT. junk). I usually end up putting the ORIGINAL OEM part back on when the AFT. part fails. I know I should have saved that for a separate thread, but I had to vent. I always ran NON-USA carbs and distributors. Alot of people don't realize that most LC's don't have vacuum advance (only the really old ones and the late 70s on). Anyway, The 3FE head on a 2F was my original plan. In the end, having discussed this with mechanics, I concluded that the GM TBI was cheap, reliable, proven, and easy to program, fine-tune etc. Parts everywhere. You could literally break down in the middle of nowhere and get a ECU, and any other part from a parts house or junk yard-no problem. I almost had a custom Multiport built, but decided against it. Theoretically it could/would be better, but again, mechanics and others convinced me TBI was simpler and that the advantages of multiport were exaggerated.
Let me speed this up a bit...okay, anyway, once I made up my mind I ordered a few parts and began the TBI project. I want to emphasize that my truck was running GREAT before this upgrade. (I had a brand new Weber 38/38). I didn't expect much really. Boy was I in for a surprise. The EFI made my truck run like a totally different engine and tranny were installed! You actually have to drive it to know what I mean. I would go so far as to say that my 40 feels more powerful than my 4.5L FZJ80. Also, unlike the 80, I can program the GM with my pocket programmer. TUrn on or off EGR, whatever I want. I currently have a spare computer, spare manifold adapter, and even a spare TBI!!! Why? Well, I have a hobby and love spending money on my cruiser! I just put in a brand new Throttle body (650cfm holley actually). I also bought someone else's fine-tuned ECU. I found out that any ECU out of a late eighties-early nineties GM w/4.3L v6 worked great in the 2F as-is. The absolute best advice I can give anyone regardless of 3FE->2f or GM TBI, whatever is: GET A WIRING HARNESS! Painless is TOTALLY worth it. Awesome investment. Finally, I have a hookup on getting the O2 sensor welded in. I run headers and found that you have to use a heated O2 sensor.
Finally, if you seriously decide to do the GM TBI, I'd be happy to help. I currently run the custom DUI HEI distributor (not the regular HEI, but the one for TBI), a Vehicle speed sensor, heated O2 sensor, MAP, temp and knock sensor (though I'm considering disabling that). The hardest part to me was getting the throttle linkage right. I'm currently about to redo mine. Also, I hate running an Open air cleaner, and I'm NOT a K&N fan. I plan to put an FZJ80 air box on mine (if I can find the room!) since its free flowing (unline the '78) and has the dust collector and water proof (like the diesels).
Whew! nuff said for now. In the end, the cruiser starts in the garage with virtually No smell, and has incredible drivability and power...can pass on uphills turning huge tires, etc...no more whine when letting off the gas in lower gears, etc...actually wants to hold you there instead...very nice.