1979 K20 5.3 Swap

[Honky Kong jr]

Oh and don't delete the rearO2 sensor signals... It affects driveability and tuning by AFR.

A rear O2 sensors job is to monitor the cat. If you get a cat code it is registered by the rearO2. The front O2 is what controls air/fuel mixture.

 

[rpcraft]

Sorry, my bad.... Yes, keep the front. I was looking at pictures and did not think about the fact that my picture was taken standing behind the motor.... Whoopsie.

 

[smurfasaur]

Yeah I have just the rear o2’s deleted. I’m thinking about trying wiring both front o2’s to the drivers side and seeing what happens. Worst case is it throws a code and I wire up the passenger side.


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[rpcraft]

I don't think that will work to be honest... It's looking for specific voltages and twisting them together is going to screw up its feedback or cut it off entirely and do nothing but throw codes. Why not just cap off the old bung and put another one in a better spot or rotate your collector on the header?

FYI turbo ricers get away with it because they only have one bank and usually only one front O2 sensor. You got two. If the left side and right side don't receive appropriate AFR feedback then it can't tune separately and it's not ever really going to run to max potential

 

[smurfasaur]

I don't think that will work to be honest... It's looking for specific voltages and twisting them together is going to screw up its feedback or cut it off entirely and do nothing but throw codes. Why not just cap off the old bung and put another one in a better spot or rotate your collector on the header?

FYI turbo ricers get away with it because they only have one bank and usually only one front O2 sensor. You got two. If the left side and right side don't receive appropriate AFR feedback then it can't tune separately and it's not ever really going to run to max potential

I don’t think rotating the collector will work because there is a pretty good jog in them to the drivers side... maybe if I had a welder that could do stainless. Capping off the old bung won’t work either unfortunately because the cap actually won’t fit on with the front driveshaft hooked up to the tcase.

I see your point with each sensor needing individual AFR feedback, I guess I’ve always just been skeptical how much they actually matter lol


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[rpcraft]

Sorry if you have said this already but what headers are you using that it's causing these issues? As in what brand, sorry if I was not clear on that.

 

[Frankenchevy]

I don’t think rotating the collector will work because there is a pretty good jog in them to the drivers side... maybe if I had a welder that could do stainless. Capping off the old bung won’t work either unfortunately because the cap actually won’t fit on with the front driveshaft hooked up to the tcase.

I see your point with each sensor needing individual AFR feedback, I guess I’ve always just been skeptical how much they actually matter lol


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I don't know a bunch about the 5.3, but I think the o2 sensor is pretty much everything when it comes to efi working correctly.

 

[rpcraft]

In case you are wondering why the rotation is essentially to keep water and moisture out of the O2 sensors and fouling them.

 

[rpcraft]

FWIW I am using speed engineering short headers on my LS swap and they were originally listed for Camaro style headers as well. Even without the v-band clamps this was the orientation of my O2 sensor. I had more issues on the drivers side using the stock shift linkage (auto trans) but overall I think I have it sorted out now with the Vband clamp. I have the parts off right now because I'm going for paint and beautification once my house is finished so my swap is kind of on hold but I can put them back on this weekend and take some pictures if you like. It doesn't take but about 30 minutes or so now. The reason I point this out is because Speed Engineering now has a proper truck header and they come with the V band clamps and they are still under 200 USD, and although they are short style headers, you are not going to see a huge difference between the long tube vs the short style and it might be a good way to resolve your conflicting issues.

It sucks to have to re-purchase items, but welcome to the swap club, lol.

Ignore the big hunk out of my frame there. It's from test fitting the factory manifold and I'll stitch it back up before I paint anything.


Here is a photo of my garbage at the last time i had it mounted with the original collectors:

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[smurfasaur]

Dang I wish I knew about those headers you’re describing before I bought mine! Mine are no name eBay headers but they’re actually pretty nice and they’re stainless, just don’t fit great haha

I’m going to try to make it work with the ones I have first and if I can’t I’ll definitely look into those speed engineering ones. Thanks man!


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[smurfasaur]

Just looked up speed engineering and damn those are slick. I really like the vband with the piece the connects to it having the o2 sensor bung in it so you can rotate it however you need


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[roundhouse]

I don’t think it will run right with a o2 sensor missing
It’s looking for two different feedbacks

Imanaged to hook mine up backwards and the engine would not run after it reached operating temp

 

[Honky Kong jr]

Yeah it needs s to see afr and load signals

 

[smurfasaur]

Ok so for the first startup I just took off the front driveshaft so both the o2’s will fit in their bungs. Going to tackle building the exhaust after I make sure my harness and fuel system will run.

Going a little unconventional for my fuel system. I have a walbro external pump pulling fuel through the selector valve to a corvette regulator which sends its return back to the return on the selector valve. Haven’t seen anyone else do this with dual tanks most people get the tbi sending units and a high pressure selector valve.

I probably would’ve gone the tbi in tank pumps and new selector valve, but I ordered a bunch of parts at the beginning of the swap and then came across people doing the tbi pumps. Another “don’t do what I did” moment, lol


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[Calvin curry]

About to start on my 85 k10 SWB. Putting 6.0(lq9 with 4l80 and np241 t-case. I ordered a hooker Mtr mounts & hooker trans crossmember for a c10. I had read on a few other forums that it work with a k10 no mods to it. If not I'll send back and build one. Would like to see what you work up for it yours.