[JLMounce]

To my knowledge there are only currently two tri-power EFI kits on the market. FiTech and AutoTrend. I don't know a lot about AutoTrend, but they cater traditionally to high end street rods. Their hardware is probably similar to the FiTech, but I have no clue on what kind of engine management they use. If you're going to a stock carbureted type look in an EFI Tri-Power package, the AutoTrend will probably look the part a bit better. That said, expect to probably pay at least double what the FiTech system goes for.

I've answered your other questions belwo.

1. Do I need a new intake? You shouldn't need a new intake and on a stockish engine I wouldn't mess with anything aftermarket.

2. What kind of fuel pump would I need? You should use a quality in-tank pump. For a stockish 389 I would use a TI Automotive Walbro 255. Make sure to buy from an authorized distributor, there's lots of counterfits of these pumps.

3. Would my stock gas tank work? Do I need a return line? It will work, but it's not the best option for an in-tank pump. If you decide to modify the original tank, I would look at something like the Tanks Inc PA series which adds a small, but important internal sump. There is also the Aeromotive Phantom kit which is decent if this car is only a cruiser and isn't seeing strong drag strip runs or lots of turns. Resist the urge to try and use a frame-mounted fuel pump or one of those under-hood auxiliary reservoirs. In regards to a return line, plan on running new fuel lines front to back. You'll want something in the 3/8" or -6AN size. For either the FiTech or AutoTrend setup you'll need a fuel pressure regulator as well. I don't know what pressure the AutoTrend unit runs on, but the FiTech runs on 4bar pressure (58psi). That means you can run the "Corvette" filter and pressure regulator. That filter has the feed, regulator, filter and return built in to it and is an off the shelf OEM part. You can mount it near the tank and run a short return line, with a single feed line to the engine. Done correctly, you can make this type of setup look almost like factory.

4. Does any one have this set up on their 66 GTO tri-power? I see lots of the FiTech units out and about and have a FiTech myself. All of the software and hardware is primarily the same, it's just in a different form factor. I also see the AutoTrend stuff on a lot of cars around here by virtue of being located close to Pinkees Hot Rod Shop. I have no direct experience with their systems however. My FiTech has been on my car and running for a decade.

5. What would be the best EFI tri-power? I wouldn't hesitate to go with the FiTech Tri Power setup. The only thing that would steer me to spend more on the AutoTrend is if there was a need to get as close as possible to the factory type look. I would take the money saved there and put it towards a brand new fuel system that included a new EFI ready fuel tank from somebody like Tanks Inc or Rick's Tanks and a well thought out and installed fuel system.

I can't emphasize this enough, it's the fuel system that makes or breaks these things. 90% of the problems that come up with these TBI units is related to improper installation and poor half-assed fuel systems.