How hard is a Carb to TBI conversion?

[Scott26]

im thinking about getting rid of the quadrajet and puting a tbi motor in. Would i have to buy a 87 and up crate engine.or could i buy the painless wiring conversion kit and then get a throttle body off a donor truck? Is this to hard of a job for a average backyard machanic?.

[wyattglock]

If you are not looking for a stock style 2 barrel setup, there are a couple of different aftermarket 4 barrel tbi units. I personally havent used any of them, but I am sure some of the guys on here could chime in with some advice. I know Holley, FAST, Accel, and Edelbrock all have complete systems. If you are working on a tighter budget than that, a donor vehicle of at least a 1987 would get you all you needed.

[lindstromjd]

Wiring harness and ECU would get you what you wanted. You'd also have to get an intake adapter, because of the way the TBI's bolt in. The TBI intake requires heads with top-style valve cover bolts, and the carb intakes are usually side-style.

[355bullet]

check it out, here are some kits.
my friend adapted the tbi for his v8 jeep. And its an amc engine
http://www.affordable-fuel-injection.com/

[pooods]

Stick with the Q-jet over a stock TBI system. The only advantage I have ever noticed is better cold weather starting and possibly a MPG improvement. However, the Q-jet is easy to work on and when in good condition it will start good and have more power than any TBI I have driven. The TBI just dies about 4k RPM's. Not having all the sensors and problems coming along with them is priceless IMO.
The Holley TBI is a better performer. Not cheap but a nice system. Tunable and can adapt to future mods well. Still more aggravating to work on than a carb though.

[Jonboy]

I am in the middle of doing this very swap on my '74. A buddy of mine is upgrading to an LS in his '87, so I decided to run his old TBI stuff vs. going LS. I found a lot of good tech here: http://www.binderplanet.com/forums/f...splay.php?f=75 , and here: http://67-72chevytrucks.com/vboard/s...d.php?t=352321 .

I used the wiring harness from fuel injection connection. It is all new, and was relatively inexpensive, at $245. It is labeled, and it is a really nice harness. Robert has answered any questions I have had pretty quickly, too. Their site is www.fuelinjectionconnection.com . I also had teh luxury of having an '87 parts truck, but the engine, trans, ecm, and harness were long gone. I pulled the fuel tank, but with TBI you could probably either run an external pump, or just buy a new tank & sending unit. The lines in my parts truck weren't all that great, so it wasn't much of a bonus there. You can get most of what you need from a 87-up Suburban or Blazer, too. Not sure about your area, but they are fairly plentiful in the pick a parts here.

The binderplanet site is pretty cool in that a lot of teh guys there are adapting the GM TBI for use on their existing IH engines. Compared to that, we have it easy. I feel like I wussed out buying a new harness compared to those guys....

[Jonboy]

That is a lot of the reason I went with the FIC harness. I know I could build my own, I just don't have the time to do it.