I was just on jtr.com and they had a 97 S10 with a 97 350 vortec and they said they used the vortec 350 computer with the 4.3 wiring, just adding an O2 sensor and 2 injector connectors. I was going to get a 01-02 savanna van ECM at the JY, but I may do more research before re-pinning it.
How to swap a Vortec 350 into a 4.3 S10/Sonoma
Doing a little write-up while it is fresh on my mind. This will be specific to 2000-2003 s10 with the 0411 silver computer and 2wd......but a lot of info will cross over into other years.
First, the engine:
You want 1996-2003 350 out of a full-size truck or an express/savanna van. If it is out of a 2500 or larger pickup, you must change the oil pan to 1500. It will not clear the cross-member.
Things you want to do before install to the 350:
Well, make sure it is a good engine. If it has too many miles on it, I will rebuild it just for peace of mind, even if it is a good running motor. You do not want to be pulling this motor again in 20k miles.
AT THE VERY LEAST, change the intake gaskets.
I would also recommend changing the spider injector to the updated version.
Check the distributor gear for wear and the shaft for side-to-side play.
Change the water pump. They are $40 for a brand new one. Again, peace of mind.
PAINT IT. This will make it look much, much better when installed.
Things you will need before you start this:
Motor mounts.
Many different companies make them, including JTR and Current Performance. I went with the JTR.
Headers.
Four options here. Hedman, Sanderson, eBay stainless.....all shorties. Or, if you dare(you will have to move your fuel lines), long tubes. I used the Heddmans. You have to specify bigger flanges with the heddmans. They come with 2".
Radiator.
Most people use the 1986-ish Corvette radiator. This requires cutting on the core support. And requires an adapter for the lower radiator hose. I used the stock 4.3 radiators. I figured if I had to cut, I might as well make my stock one work. That way, I could use the stock tranny cooler and oil cooler. There are other options that do not require cutting. Current Performance makes one that fits in the stock location. But it was 500 bucks. I will post pics of the stock radiator frenched later in this post.
Fan.
I used the stock clutch fan that was on my 350. My 350 came out of 1996 2500HD. You may want to go with an electric fan...I will be later when money allows.
Here are the electric fan options.
Using the stock radiator(16x26 inches), a 2000-ish Dodge Intrepid fan will fit PERFECT. And I will keep it cool. Also only pulls 14-16 amps. Also, a mid 90's Volvo fan will fit perfectly.....but pulls around 40-50 amps. You can also use an early-mid 90's Nissan Quest fan. It fits like stock and pulls only 20 amps.
If you go with the Corvette radiator(16x23 inches), your options change. A ford Taurus fan fits it perfectly. The 1995 and below single fan dual speed ones. You can also mod the Nissan Quest fan and make it fit.
The biggest thing to remember here is 1 or 2 aftermarket fans without a shroud WILL NOT COOL IT WITH AC. You must run a shrouded setup to get maximum airflow over the radiator.
AC condenser.
No matter what, when you move the radiator forward, your stock condenser will not work anymore. Some people modify the hood latch bracket and move it to the front of the core support. Another option is the Current Performance one. It will fit behind the core support.
Computer.
With a 2000 and up, you can use your factory 0411 computer. It will need to be reflashed. Many places do this. I tried Wait4me and got screwed. It did not work. Engine only ran on five cyl. I now have a Current Performance computer, and it runs great.
Companies that do this:
Pcmforless
Current Performance
Black Bear Performance
And many others...
Harness.
From 2000-2003, use your 4.3 harnesses. You only have to add the two injector wires, a one-wire knock sensor, and separate the low side ground for the O2 sensors. I will get into wiring specifics later.
Tranny.
The 4L60E will work fine. I am sure the 5-speed will work fine too. You will have to get different bell housing bolts. The 4.3 are metric, and the 350 are not.
Starter.
The stock 4.3 starters will work fine on either flexplate as long as the 5.7L was from a 1500 truck with 4L60e. My engine was from 2500 with 4L80e, so I could not use the flex plate. Again, the bolts on the 4.3 are metric, and the 350 are not.
OK......next post will concern installation. More to come.
First, the engine:
You want 1996-2003 350 out of a full-size truck or an express/savanna van. If it is out of a 2500 or larger pickup, you must change the oil pan to 1500. It will not clear the cross-member.
Things you want to do before install to the 350:
Well, make sure it is a good engine. If it has too many miles on it, I will rebuild it just for peace of mind, even if it is a good running motor. You do not want to be pulling this motor again in 20k miles.
AT THE VERY LEAST, change the intake gaskets.
I would also recommend changing the spider injector to the updated version.
Check the distributor gear for wear and the shaft for side-to-side play.
Change the water pump. They are $40 for a brand new one. Again, peace of mind.
PAINT IT. This will make it look much, much better when installed.
Things you will need before you start this:
Motor mounts.
Many different companies make them, including JTR and Current Performance. I went with the JTR.
Headers.
Four options here. Hedman, Sanderson, eBay stainless.....all shorties. Or, if you dare(you will have to move your fuel lines), long tubes. I used the Heddmans. You have to specify bigger flanges with the heddmans. They come with 2".
Radiator.
Most people use the 1986-ish Corvette radiator. This requires cutting on the core support. And requires an adapter for the lower radiator hose. I used the stock 4.3 radiators. I figured if I had to cut, I might as well make my stock one work. That way, I could use the stock tranny cooler and oil cooler. There are other options that do not require cutting. Current Performance makes one that fits in the stock location. But it was 500 bucks. I will post pics of the stock radiator frenched later in this post.
Fan.
I used the stock clutch fan that was on my 350. My 350 came out of 1996 2500HD. You may want to go with an electric fan...I will be later when money allows.
Here are the electric fan options.
Using the stock radiator(16x26 inches), a 2000-ish Dodge Intrepid fan will fit PERFECT. And I will keep it cool. Also only pulls 14-16 amps. Also, a mid 90's Volvo fan will fit perfectly.....but pulls around 40-50 amps. You can also use an early-mid 90's Nissan Quest fan. It fits like stock and pulls only 20 amps.
If you go with the Corvette radiator(16x23 inches), your options change. A ford Taurus fan fits it perfectly. The 1995 and below single fan dual speed ones. You can also mod the Nissan Quest fan and make it fit.
The biggest thing to remember here is 1 or 2 aftermarket fans without a shroud WILL NOT COOL IT WITH AC. You must run a shrouded setup to get maximum airflow over the radiator.
AC condenser.
No matter what, when you move the radiator forward, your stock condenser will not work anymore. Some people modify the hood latch bracket and move it to the front of the core support. Another option is the Current Performance one. It will fit behind the core support.
Computer.
With a 2000 and up, you can use your factory 0411 computer. It will need to be reflashed. Many places do this. I tried Wait4me and got screwed. It did not work. Engine only ran on five cyl. I now have a Current Performance computer, and it runs great.
Companies that do this:
Pcmforless
Current Performance
Black Bear Performance
And many others...
Harness.
From 2000-2003, use your 4.3 harnesses. You only have to add the two injector wires, a one-wire knock sensor, and separate the low side ground for the O2 sensors. I will get into wiring specifics later.
Tranny.
The 4L60E will work fine. I am sure the 5-speed will work fine too. You will have to get different bell housing bolts. The 4.3 are metric, and the 350 are not.
Starter.
The stock 4.3 starters will work fine on either flexplate as long as the 5.7L was from a 1500 truck with 4L60e. My engine was from 2500 with 4L80e, so I could not use the flex plate. Again, the bolts on the 4.3 are metric, and the 350 are not.
OK......next post will concern installation. More to come.
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411's came in multiple vehicles, read the link I posted from gmtruckcentral.
I didn't have to add an o2 sensor wire, but did have to add the two injector wires.
I didn't have to add an o2 sensor wire, but did have to add the two injector wires.
They didn't specify the 411, but the 97 vortec ECM, so that's why I'm asking why that can't be used instead of the 411.
411 pcm' scan do more and faster. Imagine playing a Playstation 1 and then a Playstation 4. The difference would be comparable.
Hi, thanks for your detailed documentation.
I started my own thread with a few questions that are specific to my year vehicle which is an 04 4.3 ZR2 4X4 Blazer. Do you know what V8 engine block will work best for my truck? I am hoping there is something out there that will work without me having to modify or add adapters to the motor mounts. That way I can focus on rebuilding the engine with hot rodded parts. If you are interested in chiming in on my thread I would appreciate it. The link is here:
http://www.s10forum.com/forum/f10/newb-v8-conversion-questions-722073/
Excellent work on your truck! I love the old school top mount air filter. I will totally use the same block you did if fits in my truck.
-JP
I started my own thread with a few questions that are specific to my year vehicle which is an 04 4.3 ZR2 4X4 Blazer. Do you know what V8 engine block will work best for my truck? I am hoping there is something out there that will work without me having to modify or add adapters to the motor mounts. That way I can focus on rebuilding the engine with hot rodded parts. If you are interested in chiming in on my thread I would appreciate it. The link is here:
http://www.s10forum.com/forum/f10/newb-v8-conversion-questions-722073/
Excellent work on your truck! I love the old school top mount air filter. I will totally use the same block you did if fits in my truck.
-JP
I've been looking on the forum for step by step stuff for using 96 4.3 ECM and wiring for 350 and haven't had much luck. I found lt1swap.com and there is a lot of good info for an old fart like me. I'm hoping to get rid of most of the wires before I put it in my 82. Thanks for trying to help everyone, some sank in and some just flew right over my head, but one thing you can count on here, is that er'one tries to help. 
If you need anything else just ask.
Thanks Justin!If you need anything else just ask.
If I have a 96 4.3 and get a 96 5.7 ecu and wire harness, what all needs to be done for the wiring part? Is it just plug and play or does the wiring harness from the v8 need to be extended. It's not to clear from what I read.
Somebody was thinking about it, but wasn't too clear. Any feedback would be nice.So is there a certain reason you can't just use the computer from whatever vehicle you get the motor out of? Then just pin in your select few wires and drive the thing. Or is there something in the leftlock to where you can't do that?
Just wondering cause I have an 02 Chevy express w/5.7L in the back yard that's wrecked. Also have a 99 GMC Jimmy/Envoy edition I wouldn't mind doing this swap on.
If you have a 2nd gen with a 4.3 Vortec engine then you re-use that harness. You do not need the 5.7 harness at all and you do not need the 5.7 pcm. You need the 5.7 injector pod, some wire for the extra 2 injectors, 2 new grounds, and some pins for the plugs and pod.
-If you have a 1996-00 model then you can use your pcm(or do the 411 swap; however, I believe some 00 models had the 411's.), but it will need to be reflashed so that it thinks it's in a fullsize truck.
-If you have a 2001-05 model then you can use your pcm, but it will need to be reflashed so that it thinks it's in a 2002 Express van.
It's best to just get a 411 pcm and repin your harness then have the 411 pcm re-flashed for a 2002 express van tune. You use the Express van tune because it's the only model that used the 411 PCM and 350 Vortec together.
The black box is older technology so you can't do as much with them vs the 411's. Your harness is already out, a 411 with plugs isn't all that expensive, you can sit in your living room and repin it all so there's no reason not to.
My 411 has various tunes from different vehicles and you might have to do the same, this goes for both PCM's.
-If you have a 1996-00 model then you can use your pcm(or do the 411 swap; however, I believe some 00 models had the 411's.), but it will need to be reflashed so that it thinks it's in a fullsize truck.
-If you have a 2001-05 model then you can use your pcm, but it will need to be reflashed so that it thinks it's in a 2002 Express van.
It's best to just get a 411 pcm and repin your harness then have the 411 pcm re-flashed for a 2002 express van tune. You use the Express van tune because it's the only model that used the 411 PCM and 350 Vortec together.
The black box is older technology so you can't do as much with them vs the 411's. Your harness is already out, a 411 with plugs isn't all that expensive, you can sit in your living room and repin it all so there's no reason not to.
My 411 has various tunes from different vehicles and you might have to do the same, this goes for both PCM's.
So here's the $64,000 question-if I get a 96 Silverado engine harness and ECM, can I plug the other 4 connectors from the S10 in to the Silverado ECM and have everything work properly? This includes the lights and dash all running like a Silvy.
It's never a good thing when an engine starts by idles crappy.
Refresh my memory, what year truck is this going in and what is the current engine?So here's the $64,000 question-if I get a 96 Silverado engine harness and ECM, can I plug the other 4 connectors from the S10 in to the Silverado ECM and have everything work properly? This includes the lights and dash all running like a Silvy.
Well that's kind of what I mean, only I'll have the 350 vortec in it. You still have the V6 with a 350 ECM?You and I should be playing the lottery. I just put the 96 5.7 ecu into the 96 v6 harness hooked to the 4.3 motor. I just started it ten minutes ago. It starts but idles crappy. All the gauges worked. It's a start though.
He hasn't done the swap. He didn't even know how to mod the harness 2 days ago. Also you can't just plug a PCM into another vehicle as they're vin specific so what he's saying isn't possible.Well that's kind of what I mean, only I'll have the 350 vortec in it. You still have the V6 with a 350 ECM?
And risk putting up with drunk techs who forget I have a five speed? No thanks, I'm good.
Oh and I got the y pipe too from the Yukon, it a dual pipe, shaped like the y pipes configuration.
Oh and I got the y pipe too from the Yukon, it a dual pipe, shaped like the y pipes configuration.
I thought because the 96 doesn't have vats that they weren't vehicle specific?He hasn't done the swap. He didn't even know how to mod the harness 2 days ago. Also you can't just plug a PCM into another vehicle as they're vin specific so what he's saying isn't possible.
Well maybe, just maybe if i hook up the 5.7 ecu again will see if my cheap 96-97 hypertech pp picks up the ecu as a 5.7 with vin!
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