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How to swap a Vortec 350 into a 4.3 S10/Sonoma

272341 Views 210 Replies 56 Participants Last post by  Rhotpursuit
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.

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".

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.

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.

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:
Current Performance
Black Bear Performance
And many others...

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.

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.

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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Nothing needs to be modified on the O2's.
Just put the V6 ones back in, that's what I have.
1500's didn't have the 411 PCM so a 1500 tune won't work. The 02 and 03 Express cans had 350 vortec's and 411's.
I have a couple of questions hopefully someone can answer.

I have a 2002 xtreme blazer.

I would like this to stay DD with all instruments working. Is there a donor that is a better suitor for this than others. What exhaust size mufflers and others would be the best match for a DD not to loud setup? Is there any issues with weight? I live in Memphis and I am concerned with cooling I will want to run AC. What is the most affordable setup using some pulled used parts not the $500.00 setups?

I may have other questions but I need these to get a budget figured out

I have a 350 Vortec in mine and I drive it just about every day so you have no problem there. Any 350 Vortec will work. They mainly came in 96-98 fullsize trucks, but were also found in 1st gen Escalade's/Denali's, and Express vans.

I'm running a custom bent 2.5" exhaust coming from the headers all the way to the muffler and a turn down right behind the bumper end cap. If your state doesn't have smog tests then you can get away without running a cat.

What do you mean weight? Lowering the front more? It didn't drop my front anymore at all.

I suggest getting Dodge Intrepid fans, buy a 411 PCM, have it tuned to a 02 Express van, repin the PCM plugs, and have the e-fans turned on. Also get a 180* t-stat. I was sitting in a traffic jam in 100+ degree weather a couple weeks ago and mine didn't overheat.

What is the most affordable setup using some pulled used parts not the $500.00 setups?
I'm using a new stock radiator, I guess it's HD, because when I got it it was thicker than the original one. Also I'm running Dodge Intrepid e-fans.
If the engine is in good shape that's a good deal. I did wait4me, they screwed it all up so I bought HPtuners and did it that way. pcm4less is a could company to go through though. Yeah the PCM will work, I thought the S10's all either had black boxes or 411's though.
No I don't have the part number. I just ordered it from autozone and noticed it was much thicker than the original one.
You don't have to do anything other than run the injector wires. Once that's done all you do is flash your 411 with an 02 Express van tune.
I think you can send the PCM off to pcm4less and they'll reflash it for around $100. Tell them what you're doing and also tell them to turn the Efans on (at what temps you want) that way you can run your fans off your PCM and not need a controller.
Idk, mine worked right off the bat.
You don't want to do that. Put a 5.3 in it. That swap will give you more power, better mpg, and will be A LOT easier to do.
So I searched a little and found this.
and this

So it can be done, but it's redundant. It would be like putting a 1st gen s10 front clip on a Colorado. If I had to do it over again I'd get a 5.3 instead of my 350 Vortec. The L31(350 Vortec) puts out 250hp. Not that much difference for all the work and money it takes to do the swap. I'd suggest you find a wrecked nbs with a 5.3 for cheap and just swap everything over. You can get a lot more power out of the newer engines than the L31's.
Who did you the black box to 411 box spreadsheet from? When you did the swap did you do one wire at a time? I can't go on the wire colors, but if you tell me the wire number on the S10 plugs then I should be able to help you. I have some left over as well.

You'll need to have the PCM programmed for an 02 Express van tune with either your vin or no vin at all.
I cannot remember the wires and I just left them connected to the old plugs. Who did you get the spreadsheet from to do the swap?
Okay to begin I just noticed my file is for a 98-00 model 350 Vortec 411 swap. It would be best to go to look up Lextech on here and shoot him a pm on the spreadsheet you need. For the hell of it though I want to see if the wires are the same color.
2 - White
5 - not used
6 - light green
7 - brown
29 - light green/black
25 - dark green
21 - light green

Again my file is for 98-00. You need to see if he has one for 96-97.
Keep your 4.3 harness and mod it. Get a 411 PCM and connectors then have it flashed for an 01 or 02 Express van tune. I'm almost positive I'm using the stock o2's. I think they're the same part#.
No, the V8 PCM will have the V8 tune, but it will only work in the vehicle it came off of because they're VIN specific. A 411 PCM is like a PS4 vs an Atari. The 411 is a faster PCM that you can do more with. A cluster from something that a 5.7 came out of won't fit a S10, think about it. You can reprogram your stock 4.3 PCM, but it's better to go with a 411 since you're already doing all the other work.

Yes, 4L60e's are the same between the two engines.
You'll have to mod the shape of the cluster and probably re-wire the entire plug. Unless you're talking about a 99-02 Silverado cluster in which cause you can swap them out, but those didn't have 5.7's in them.

Polish up the 411 PCM and it looks really nice.
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