4.3 to 5.3 engine swap?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Damien · 01-22-2010, 07:31 PM

I have a friend at school that is thinking about getting rid of the 4.3 in his '05 chevy 4.3 v6 5 speed, I'm thinking this may be a fairly simple swap, just change the harness and computer and drop in the engine with v8 specific parts. We located a complete 5.3, computer and harness for $750. I think he is going to need the following:
Fan
throttle cable
engine mounts
flywheel
air intake pluming
modified exhaust

Anything else you guys can think of? Will it work to swap the harness?

**truckdude239** · 01-22-2010, 09:35 PM

sounds about right its is doable

clinebarger · 01-23-2010, 10:41 PM

Quote:

Originally Posted by Damien

I have a friend at school that is thinking about getting rid of the 4.3 in his '05 chevy 4.3 v6 5 speed, I'm thinking this may be a fairly simple swap, just change the harness and computer and drop in the engine with v8 specific parts. We located a complete 5.3, computer and harness for $750. I think he is going to need the following:
Fan
throttle cable
engine mounts
flywheel
air intake pluming
modified exhaust

Anything else you guys can think of? Will it work to swap the harness?

Are you staying with the 5-speed, if so the flywheel will not work as you know, & crank spacing is different, not sure what problems you will run into on the clutch.

The tach in the cluster will be off.

You will need engine mount stands as well.

What year 5.3 are you going to use?

If you get a 4.8/5.3 Y-pipe it will bolt up to the stock exhaust

Damien · 01-23-2010, 11:04 PM

We found a '03 engine. As far as I know, the 4.3 is still a cable operated throttle body. so I think an older 5.3 will be the easier way to go there. I know nothing about the input shaft lengths on the trans, but the idea was to keep the 5 speed. So he should look into getting a v8 interment cluster? I don't know if it has a tach. It is just a work truck, so no power anything and a vinyl floor mat.

Bamm · 01-24-2010, 01:34 PM

Would it be easier/cheaper/quicker to just sell the truck with the 4.3 and find one with a 5.3? Don't mean to offend, just throwing it out there....Jerry

clinebarger · 01-24-2010, 02:46 PM

Quote:

Originally Posted by Bamm

Would it be easier/cheaper/quicker to just sell the truck with the 4.3 and find one with a 5.3? Don't mean to offend, just throwing it out there....Jerry

I agree with that.

Damien · 01-25-2010, 03:16 PM

I know, But its not my truck and he asked about putting a different engine in. I was just wondering if anyone had done the swap. Would anyone suggest getting a different truck if I would have asked about swapping a 8.1 or LS7? He did mention the 8.1 swap, but I don't think that his budget will allow.

07HDClassic · 02-06-2010, 12:20 AM

I believe that in 03 GM switched to fly-by-wire and got rid of the cable operated throttle body. just an FYI

Mister laugh · 02-11-2010, 06:38 PM

a 5.3 is a bit too much power behind the NV3500 that is surely behind the 4.3.

Damien · 02-11-2010, 10:53 PM

Really? So it would be better to look for the 4 spd that came with the 5.3? This isn't looking like a budget swap anymore is the tranny needs to be changed.

clinebarger · 02-13-2010, 08:41 PM

A NV3500 will hold in a 1/2 ton truck if you dont abuse it.
Ive done some research and i believe a gen III piolit bearing drivin in at the right depth will work. heres some specs on the NV3500.

1st 3.49
2nd 2.14
3rd 1.38
4th 1.00
5th 0.73
R 3.55

Manufactured by New Venture Gear
Input torque rating: 340 ft-lb
Max GVWR: 7,200 lb
Max GCVWR: 11,000 lb
Fluid Capacity: 2.0L
Weight (with oil): 110 lb

Mister laugh · 02-19-2010, 04:34 PM

It may hold it it may not, however GM NEVER put a 5spd behind a 5.3 becasue their engineers didn't think an nv3500 would hold up, and a 4500 is too much behind a 5.3. It will bolt right up if you can find a flywheel but i have faith in GM's decidion making for the most part and personally wouldnt put a stock nv3500 behind a 5.3.

01-22-2010, 07:31 PM	#1
Damien Registered User Join Date: Mar 2007 Location: Farmington, MN Posts: 928	4.3 to 5.3 engine swap?? I have a friend at school that is thinking about getting rid of the 4.3 in his '05 chevy 4.3 v6 5 speed, I'm thinking this may be a fairly simple swap, just change the harness and computer and drop in the engine with v8 specific parts. We located a complete 5.3, computer and harness for $750. I think he is going to need the following: Fan throttle cable engine mounts flywheel air intake pluming modified exhaust Anything else you guys can think of? Will it work to swap the harness? __________________ I can still count my vehicles on two... wait three hands.

01-22-2010, 09:35 PM	#2
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	Re: 4.3 to 5.3 engine swap?? sounds about right its is doable __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

01-23-2010, 11:04 PM	#4
Damien Registered User Join Date: Mar 2007 Location: Farmington, MN Posts: 928	Re: 4.3 to 5.3 engine swap?? We found a '03 engine. As far as I know, the 4.3 is still a cable operated throttle body. so I think an older 5.3 will be the easier way to go there. I know nothing about the input shaft lengths on the trans, but the idea was to keep the 5 speed. So he should look into getting a v8 interment cluster? I don't know if it has a tach. It is just a work truck, so no power anything and a vinyl floor mat. __________________ I can still count my vehicles on two... wait three hands.

01-24-2010, 01:34 PM	#5
Bamm Cowboy Fan for Life!!!!!! Join Date: Apr 2002 Location: Amelia, Virginia Posts: 2,921	Re: 4.3 to 5.3 engine swap?? Would it be easier/cheaper/quicker to just sell the truck with the 4.3 and find one with a 5.3? Don't mean to offend, just throwing it out there....Jerry __________________ 1967 ShortBed Fleetside 3/4 Drop 350/700R4 Tilt wheel 18 x 8 Torque Thrust II's Future mods: All new gauges & wood bed My Zip is 23002 I ship UPS, USPS

01-25-2010, 03:16 PM	#7
Damien Registered User Join Date: Mar 2007 Location: Farmington, MN Posts: 928	Re: 4.3 to 5.3 engine swap?? I know, But its not my truck and he asked about putting a different engine in. I was just wondering if anyone had done the swap. Would anyone suggest getting a different truck if I would have asked about swapping a 8.1 or LS7? He did mention the 8.1 swap, but I don't think that his budget will allow. __________________ I can still count my vehicles on two... wait three hands.

02-06-2010, 12:20 AM	#8
07HDClassic Registered User Join Date: Oct 2009 Location: Poulsbo/Pullman WA Posts: 17	Re: 4.3 to 5.3 engine swap?? I believe that in 03 GM switched to fly-by-wire and got rid of the cable operated throttle body. just an FYI __________________ Brandon 2007 Chevrolet Silverado Classic 2500HD CCSB Duramax/Allison - 62K, Graystone Metallic - 6 inch Fabtech Lift, 5 inch Skyjacker rear leafs - 35x12.5 Toyo MT on 18"x9.5" AR Mojaves 1997 Chevrolet S10 ECSB 4.3/4L60E - 128k, Silver Metallic w/ Dark Charcoal Metallic Stripes - Bagged, Custom Paint, Large Stereo, Custom Bed, Etc... 1967 Chevrolet C10 RCLB 327/TH400 - 82k, White - A rainy day project to finish... when there's time

02-11-2010, 06:38 PM	#9
Mister laugh Registered User Join Date: Jun 2007 Location: Edmonton, Alberta Posts: 423	Re: 4.3 to 5.3 engine swap?? a 5.3 is a bit too much power behind the NV3500 that is surely behind the 4.3.

02-11-2010, 10:53 PM	#10
Damien Registered User Join Date: Mar 2007 Location: Farmington, MN Posts: 928	Re: 4.3 to 5.3 engine swap?? Really? So it would be better to look for the 4 spd that came with the 5.3? This isn't looking like a budget swap anymore is the tranny needs to be changed. __________________ I can still count my vehicles on two... wait three hands.

02-13-2010, 08:41 PM	#11
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: 4.3 to 5.3 engine swap?? A NV3500 will hold in a 1/2 ton truck if you dont abuse it. Ive done some research and i believe a gen III piolit bearing drivin in at the right depth will work. heres some specs on the NV3500. 1st 3.49 2nd 2.14 3rd 1.38 4th 1.00 5th 0.73 R 3.55 Manufactured by New Venture Gear Input torque rating: 340 ft-lb Max GVWR: 7,200 lb Max GCVWR: 11,000 lb Fluid Capacity: 2.0L Weight (with oil): 110 lb

02-19-2010, 04:34 PM	#12
Mister laugh Registered User Join Date: Jun 2007 Location: Edmonton, Alberta Posts: 423	Re: 4.3 to 5.3 engine swap?? It may hold it it may not, however GM NEVER put a 5spd behind a 5.3 becasue their engineers didn't think an nv3500 would hold up, and a 4500 is too much behind a 5.3. It will bolt right up if you can find a flywheel but i have faith in GM's decidion making for the most part and personally wouldnt put a stock nv3500 behind a 5.3.



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