1996 silverado to 2003 4.3 engine swap

[Ian Des]

Im swapping a 4.3 out of a silverado 2003 into a 1996 silverado trans is 4l60 e. Out of a 1998 jimmy they changed transmission to ls style for. 2003 4.3. Do they sell adapters for this. Or a special torque converter. Can I just use the ls to 4l60e adapter with new bell housing if I swap trans to 2003 it moves everything back 3/4 of an inch do I have to modify drive shaft trans mount

[davester]

What you are planning to do for controlling the engine and transmission?  The computer setup in the '03 is pretty integrated between the engine computer, transmission computer, body computer and instrument cluster, so you would have to hack up the interior try to get the body computer and instrument panel from the '03 into there.

 

And the transmission computer will expect to be controlling an '03 4l60e, as GM seems to have constantly been changing how they work.

 

Moving the transmission mount if necessary is the least of your problems...

[Ian Des]

23 minutes ago, Ian Des said:

Im swapping a 4.3 out of a silverado 2003 into a 1996 silverado trans is 4l60 e. Out of a 1998 jimmy they changed transmission to ls style for. 2003 4.3. Do they sell adapters for this. Or a special torque converter. Can I just use the ls to 4l60e adapter with new bell housing if I swap trans to 2003 it moves everything back 3/4 of an inch do I have to modify drive shaft trans mount

 Will the 1998 computer and harness not plug into the newer engine and transmission.  The 1996 truck was already swaped to a 1998 GMC jimmy engine and trans. 4.3 vortec and 4l60e. And the 2003 is a 4.3 vortec and 4l60e all plugs seem to be the same the fuel injection system did chang in the intake but ive read quiet a bit it would work I do have 2003 harness and computer 

[Ian Des]

5 minutes ago, Ian Des said:

 Will the 1998 computer and harness not plug into the newer engine and transmission.  The 1996 truck was already swaped to a 1998 GMC jimmy engine and trans. 4.3 vortec and 4l60e. And the 2003 is a 4.3 vortec and 4l60e all plugs seem to be the same the fuel injection system did chang in the intake but ive read quiet a bit it would work I do have 2003 harness and computer 

 I read they just adapted the 4.3 to work on the ls trans which had different bell housing torque converter. And spline size 300mm. And as long as I stay away from Trans with vehicle speed sensor. Whichnis a 2005 computer should be fine trans plug is same. 

Edited January 28, 2020 by Ian Des

[davester]

The trans plug may be the same, but it's my understanding the actual electrical signals to control it are different and changed all the time, which is why when swapping 4l60e's, you need to find one from the same year as the original.

 

And a pro-tip, in general, just because a plug fits in somewhere, doesn't mean it will work properly when plugged in.  This includes the computers for the truck.

[Ian Des]

3 minutes ago, davester said:

The trans plug may be the same, but it's my understanding the actual electrical signals to control it are different and changed all the time, which is why when swapping 4l60e's, you need to find one from the same year as the original.

 

And a pro-tip, in general, just because a plug fits in somewhere, doesn't mean it will work properly when plugged in.  This includes the computers for the truck.

So what you are saying is in. There is no possible way I can make this swap work even with the 03 computer and harness in the 1996. But it was already done once from a 1996 vortec 5.7 to a 1998 4.3 v6.  And that worked till this engine started knocking 3 years later.  

[Ian Des]

Just now, Ian Des said:

 

I read alot of guys putting these engines in jeeps and they didnt have to many problems either I think this can be done with some found knowledge.  That I'm not getting. From. Davester

[Ian Des]

4 minutes ago, Ian Des said:

I read alot of guys putting these engines in jeeps and they didnt have to many problems either I think this can be done with some found knowledge.  That I'm not getting. From. Davester

I have also read that the v6 and v8 4l60e are the same 

[davester]

Yes, the 4l60e would be the same between v6's and v8's for the same year.  But the 4l60e were changed all the time between years.

 

You may be able to swap over all the sensors and intakes from your existing engine to the new one, so the existing computer will run it.

 

Think of "Vortec 4.3" as a brand name, not a description of a specific engine.  Your '98 engine is either a LF6 or L35, while the '03 engine is either a LG3 or LU3.

 

'96 and '98 were the same generation trucks, so they used similar systems, and the computers were just beginning to be used.  With the following generation of trucks, GM used completely different computer system, where all the computers in the truck talked to each other and worked together (including the one in the radio).

 

 

[Ian Des]

So next question how do I make the old 4l60e bolt to the new engine then since that's the real problem is. The trans having no controller the engine can be ran by old computer but not trans right

[Ian Des]

And what about a standard transmission

[davester]

You may be able to replace just the bellhousing of the 4l60e with one that bolts up to the new engine.

 

The 4l60e transmission definitely has a controller, as it needs one to operate.  It may be part of the engines computer or it may be separate.

 

It seems to me you are looking for an easy, low effort fix.  That would be finding a used engine that is the same as what's coming out, or a similar engine from the same generation truck (and maybe the computer that goes with it).

[Ian Des]

5 minutes ago, davester said:

You may be able to replace just the bellhousing of the 4l60e with one that bolts up to the new engine.

 

The 4l60e transmission definitely has a controller, as it needs one to operate.  It may be part of the engines computer or it may be separate.

 

It seems to me you are looking for an easy, low effort fix.  That would be finding a used engine that is the same as what's coming out, or a similar engine from the same generation truck (and maybe the computer that goes with it).

So there is a 3/4 inch difference in the bellhousing so. Do I beed a adapter for torque conv.  Just swap back to old flywheel I see something like this done on all the ls swaps 

[davester]

I have no idea w.r.t. that level of detail (adapter plates, specific flex plates or torque converters).

 

Every swap I've read about, it is a pain to get move engines between different generation trucks, which is what you are doing.

 

If you are able to swap parts on the engine to convert it to use all the older engines bits (sensors, fuel setup, etc), it might work if you get the engine to bolt up to the transmission.

[Ian Des]

2 hours ago, davester said:

I have no idea w.r.t. that level of detail (adapter plates, specific flex plates or torque converters).

 

Every swap I've read about, it is a pain to get move engines between different generation trucks, which is what you are doing.

 

If you are able to swap parts on the engine to convert it to use all the older engines bits (sensors, fuel setup, etc), it might work if you get the engine to bolt up to the transmission.

Yeah all sensors plugs are all the same on engine I think a bell housing swap and one of the kits with dished flex plate longer bolts and. Torque converter adapter starter from 03 would definitely get it going might have to switch intake too since fuel injection might be different. Do you think that would work