Before I say anything more, I am not interested in a debate about "why not just install an LS engine blah blah blah". I am a retiree who is on the thin edge financially and I do not see that changing. So, IF I want something like an operating vehicle, I need to work on it myself or go without. The possibility of the following falls into this category.

Here is the scenario - I have a '98 Chevy C1500 RWD truck that I bought new, kept up and spent money on over the last 20 years. Winter driving and twenty odd trips to the Bonneville Salt Flats took its toll (corrosion-wise) on the frame and undercarriage. I was involved in a non serious accident that bent the front bumper and crinkled the rad support on it. I was aghast at how much rust and scale fell out of the truck after this mishap! I banged everything out and got it on the road again BUT - I am not a whole lot confident about the structural integrity of the frame anymore. I had, not too long ago, replaced the original motor with a brand new 5.7 Goodwrench crate motor, I had regularly done trans filter changes and powerflushed the transmission (a 4L60E) as well as replaced the valve body that is a culprit in making the slip while shifting into overdrive. Suffice it to say that the truck should be retired - but what to do with the running gear?

Recently, I was offered a 2003 (? - It has the "pinched" headlights) Chevrolet 1500 RWD extended cab truck that has a worn out 4.3 V6 engine and automatic transmission as an even trade for another vehicle I have here. I got to looking into what it would take to install the 5.7 and automatic transmission into the '03 truck. It seems that the swap is possible but there are a host of issues with the ECM and the need for extra wiring for the extra two cylinders. I found a "blog" on another site where the writer installed a 5.7 Vortec into an '03 S-10 that was originally V6 powered. He goes into great detail about the wiring changes and the computer "reflash" (a term that scares me).

So - my questions are these - Would following the information about an S10 engine swap in an '03 model work for a full sized truck? Has anyone done this swap and, if so, how did you address the wiring issues?

Thanx

 

main question is most states down here forbid swapping an older motor into a newer truck. due to emission standards. i dont know what laws are up there north of the wall or even if you have yearly inspections

 

There are no inspections in my area. There were in the major metropolitan areas for a number of years but there was a way around it. I really don't worry too much about whether the law says I can or can't do an engine swap. The laws are not mechanical engineering principles or anything remotely related.

That aside, the V6 technology seems to be be contemporary with the V8 Vortec technology of a few years earlier. My biggest thing is trying to figure out what "pitfalls" there might be in doing the swap. It cam to me that, after the '90s body style, which hung on until the 2000 model year with crewcabs and
Escalades/Denalis (and in the vans up to 2002) there was an obvious change to "throttle by wire" instead of a cable linkage. I guess it remains to be seen. Hopefully, someone has knowledge of this stuff.

 

What you intend to do won't be cheap. The late 90's 4.3 liter Vortec motors tended to be somewhat more output then others. If you are strapped for cash there are quite a few places online that ship good used motors that have been compression tested and other tests. I don't think they have core charges, so you need not worry about any shipping costs for the old motor. Wasn't fond of the early 5.3 liter V8 and the piston slap, but Chevy took care of that issue. Seems like a 5.3 would be easier to do.

 

As far as whether or not it will be cheap, let me put it this way. I have a shop that is very well equipped with tools and equipment - including a few welders, an oxy-acetylen torch set, a fabricaitn area, a lathe and a milling machine. I have the knowledge and ability to use all of the foregoing. I have the complete vehicles, I have built hotrods, custom motorcycles and racecars for nearly 50 years. I have rebuilt quite a few other cars and trucks over the past several decades. Mechanically, the whole swap looks like a "piece of cake" to install the 5.7 engine and transmission into the newer truck. If a part does not exist for the swap, I will fabricate and/or machine it. I mean - the 4.3 is pretty much a 5.7 that has two holes and several inches of the block "missing". The '03 version of the engine even seemed to use the "same" computer as the '98 model did - with some omitted but vital wires. I do know that LS swaps have been performed "the other way" - i.e an '03 engine into a '90s truck - and the computers are relatively easily adapted to the wiring.

What, I guess I am trying to find information regarding is other "issues" - such as the so-called security features and do they somehow interfere. I have read that the security stuff can all be disabled and, thus, rendered a non - issue ... But is the electrical/electronics aspect of this swap itself really as straightforward as running some extra wires, replacing a few V8 specific plugs and reflashing the computer? The rewiring information I have is for a 5.7 V8 installation into a (formerly) 4.3 V6 powered S10. The writer claimed to have reused the V6 computer...It is things like wiring issues that have stopped me "in my tracks" on rebuilds in the past.

Mostly, I would really like to make sure I am right - most specifically in regards to the electrical - before I proceed.