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Need Help with TBI Swap Questions

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ok ive had about all i can stand from my Holley 670 Truck Avenger carb and im looking into doing a TBI swap on my 77 K5...it has a mostly stock 350 with mildly ported heads, FlowTech headers, Edelbrock intake(that im keeping, gonna use an adapter plate for throttle body) and a Melling RV cam with the following specs....278int/288exh duration with .422int/.444exh lift...im also running a TH350/NP203 with stock gears for now....im wanting to know what all i will need to swap to TBI on this engine...ive been told by several people that have done it that its is easy as hell but ive searched on here til im blue in the face and i need some help

if anyone can give me a detailed list of items i should be on the look out for it will be greatly appreciated
 
The most important part for you with the engine mods will be to get a chip burned. Other than that it is pretty easy. A lot of the stuff can come off a donor or junkyard. Find a tank pump if you can, and either change the intake to a TBI or use an adapata plate.
 
You will need, TBI unit, ECM, wiring harness, all sensors (IAC, TPS, ESC module, CTS, 02 sensor, knock sensor, and VSS sensor/cluster. You'll also need a TBI distributor and a low pressure electric fuel pump. You'll need to plumb a fuel return line back to the tank. If you're running full length headers then you'll want a heated 02 sensor. Last you'll need to have a chip burnt for the specs of your engine to run properly.
 
I'd highly suggest you look into replacing the camshaft with something that is fuel injection friendly. It is possible to get your engine to run with the one you have, but it will require pretty extensive tuning on a dyno by a professional.

TBI systems are very vaccum dependant, and are also tuned for pretty specific flow characteristics. As soon as you change a camshaft, you majorly change the flow characterisitcs of the engine, and more importantly the vaccum levels. On top of those two changes to fuel requirements, a bigger camshaft also allows a small amount of fresh air to skip the combustion process and wind up straight into the exhaust. That extra air totally wreaks havoc on the oxygen sensor at an idle, and can make idle tuning very difficult.

Its a big bother to change a camshaft and break it all in again, but the time and money saved further down the road is pretty priceless in my opinion.

As far as wiring goes, take a peek at the TBI information on www.chevythunder.com, or feel free to PM me. I've done two EFI swaps, one being a TPI setup on my 1980 K25, and the other a TBI swap on my old 77 short step. The short step ran very nicely when I finished, but the 80 lost a cam lobe on break in which caused me a so many problems that I thought it was the TPI and sold it.
 
I think the heads are different not sure about valve sizes but they are centerbolt heads.
Where can you find the adapter plate to keep your edelbrock manifold? I want to do that with mine but havent checked around yet.
 
Sweet, do you work for summit? I work at autozone and we only get 20% on in store stock, nothing on stuff we have to order.
 
lak2004 said:
Sweet, do you work for summit? I work at autozone and we only get 20% on in store stock, nothing on stuff we have to order.
Click to expand...


i wish i worked for summit

i work for Oreillys....we get most stuff at cost so the discount really helps out sometimes..that link is to an adapter like the one i can get at work
 
Any updates on your swap? I am picking up a 90 TBI long block this weekend and already have all the comp and wiring and TB to put on it.
 
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