5.3 LS into 1992K1500 OVERVIEW

[oldcarbguy]

1992 K1500 LS swap information
The recipient of the swap is a 1992 GMC K1500 (4x4) 5.7L, 700R4/4L60 trans, 241C transfer case, regular cab shortbox
The donor truck was a 2000 Silverado 1500 (4x4) 5.3/LM7, 4L60E trans, 246 transfer case
This write up is a description of what was done and what I chose to use for this swap. There are many other ways to
arrive at the same conclusion. This is just what I did and some of what I found out along the way. I do have a
mechanical service background but this is the first LS swap that I have done.
I did my own wiring harness modifications using LT1SWAP info all way. The information on that site made this swap
plenty do-able by a regular ham-n-egger like me. As stated, just be patient, use some common sense and believe what
he says. It is right and it works. I admittedly do have some wiring harness assembly background but nothing like
this 160 pin GM ECM harness. It was a bit intimidating at first, to be sure. I just figured why not give it a try? I might
learn something and if I screw it up I can still buy one. I am glad I did it, I know a little more about things now.
I swapped the fuel pump to the later year, higher pressure type. I used Evil Energy braided hose and #6 AN fittings
for the feed and return lines. This line seemed to go together nicely and when pressure tested had no leaks
anywhere. So far a thumbs up on this line. NOTE: The 2000 lm7 has fuel feed and return lines so the Corvette
fuel regulator/filter everyone talks about was not needed
I deleted the EGR system - bought the commercially available block off plates.
I used ICT Billet motor mount plates which utilize the stock 1992 steel clamshells. The plates were advertised to be
clearance cut for the raised portion of the steel clamshells. They were not. They do have an area machined out but
certainly not for this application. Still not a big deal. I cut the raised portion out of my clamshells. I positioned the
clamshells the same distance from the bell housing mating surface as the 5.7L they were taken from - thus keeping
the transmission/driveline in the same place. When placed in that position, I had to do some minor grinding on the
clamshells to clear some bolt bosses in the block. I DID NOT use the 3/16" gusset bar mounting plates that were
between the clamshells and the 5.7L block. (I called ICT to verify this)
I used the 2000 alternator, power steering pump, hoses, and bracket assembly. The power steering hoses transferred
easily with just a small amount of bending involved.
The 1992 241C 27 spline transfer case (which I wanted to use) bolted right up to the 27 spline 4L60E from the 2000
Silverado 4x4 4L60E transmission. I used the 2000 transmission to transfer case adapter housing - I don't think it
matters which one gets used. And yes, it does require a gasket between the transfer case and adapter housing. What I
found is there are 241C transfer cases with the larger 32 spline input shafts. I am not 100% sure but I think
these are to mate up with the heavier 4L80E transmissions. In other words, make sure about the spline count/shaft
sizes when choosing your components.
I chose not to use the 2000 neutral safety/range switch. I used the 1992 neutral safety switch and the 1992 purple
starter wire. At the time I hoped that I would not not regret this choice. I did it figuring there would be less wiring
conversion for the cruise control and other possible dash wiring concerns. I figured that if it all works now why
mess with it? NOTE: The TCC wire is present in the 1992 wiring harness- it's the purple wire in the 4 wire plug
connected to the 700R4, connect this wire to purple wire from #33 Blue
I had to modify (shorten 1") the 1992 transmission shifter linkage (frame to trans) to allow for the longer shift post
on the 2000 4L60E transmission.
The 2000 Silverado (4x4) VSS wiring was not in the main ECM harness. The VSS wiring that was used by the 2000
truck was in it's own separate harness which was routed from the transfer case to one of the ECM fuse block plugs
via the left frame rail. The 2000 transfer case appears to have at least 2 VSS sensors. There is a twisted wire VSS
wire pair in the main harness leading straight to the ECM but it is apparently used for 2 wheel drive applications only?
The plug on the end of that wire set was capped. I chose to use that 2 wire set figuring the 241C transfer case has only
one VSS and those wires led directly to the ECM positions shown in the LT1SWAP ECM pinout. I spliced the 1992 VSS
plug into it to mate with the 1992 transfer case sensor.
I used the 1992 15 pin white wiring connector plug located behind the 1992 glove box as a junction point for a lot of
the wiring between the 1992 dash and the 2000 ECM. This plug and wiring notes are shown in LT1SWAP.com. Use the
facebook prompt and scroll thru the posts to find it. (It is toward the end of the posts.) This was a very valuable find
for me. I did not cut off any of the "extra wires" because I was not sure what extra was.
NOTE: The DRAC module is also located behind the glove box. I will be referencing that later on.
I used the 1992 battery location, +/- cables and associated power cables to the 1992 junction block on the firewall. I
also kept and re-used the 1992 bell housing bolt mounted tin heat shield to protect the wiring in the starter area. I
re-routed the LS crank sensor wiring through this heat shield also.
I used the 1992 fuel pump relay and associated wiring on the firewall but used the 2000 ECM fuel pump relay wire
to trigger it. Cut the 1992 green/white wire, connect the 2000 green/white to it. (from 2000 ECM red #9)
I used the 2000 alternator exiter wire and plug. I don't care if I don't have an "alt" idiot light.
I used the 1992 temperature sender (single green wire in left 1992 head) and put it in the passenger side LS head
using an adapter fitting. After I had the motor in place I found that I should have drilled and tapped the head to
accept the 1992 temp sensor (3/8"NPT) I was on the verge of putting it in the water pump but after some test
fitting I found that there actually was room for it using the short adapter fitting available for this. It does fit but
ends up mighty close to the transmission tunnel/firewall.
I used the 1992 3 pin oil pressure sender and associated 1992 wiring. Thread adapter required.
I used the 2000 silverado exhaust manifolds. They fit nicely. No issues whatsoever.
I used the 2000 Silverado "Y" pipe with converters intact (for noise reduction only) The front 02 sensors have
plenty of clearance. I did not use the rear sensors. I used the bolt together flange at the end of the pipe and
enough pipe to meet up with the 1992 exhaust pipe. Cut and weld here - a bit of fiddling and hammer welding,
2 1/2" pipe to 3" pipe.
I used ICT Billet AC compressor mounts - They put the compressor in roughly the same place as the 1992 location.
I did not disconnect the hoses, just set the compressor off to the side until the motor was in place, then bolted the
compressor in place - some "massaging " of the lines is needed but nothing too drastic. With this setup a 110 1/2"
belt fit well.
The 1992 K1500 does not have 4 LOW light. A a switch could be added to address this. Set it up so that when
shifted to 4 LOW, gray/black from #16 red goes to ground
I chose to use the 1992 radiator. It has a 5/8" heater hose connection on the right side tank which I used for
the LS steam port. I made my own adapter fitting. The 2000 radiator hoses fit perfectly.
I used the stock 1992 transmission cooler lines. Had to transfer the line fittings from the 700R4 to the 4L60E.
The lines fit pretty well, just a little adjusting required.
I chose to use electric fans so I cannot confirm the stock water pump fan fit but it sure looks like it would
fit just fine.
I used the 2000 throttle cable- just a tiny bit of re-shaping of the plastic to fit the 1992 square hole
I left the 1992 cruise control module in place but installed the 2000 cable in it. Easy, squeeze the tangs, pull
out the cable, un hook it from the ribbon, replace it with the 2000 cable.
After deleting the VATS and re-setting the factory tach setting using an HP tuner - The factory tach was
reading about 1/2 the actual rpm. There is a tach setting in the tuner that showed a #6. Changing that to #3
corrected the tach.	The truck runs and drives now.
At this point I was still unsure about the speedo and cruise control electrical connections. In all my searching
I could not find any convincing evidence about how to deal with the DRAC module etc. Lots of internet chaos
about that. I decided to try just disconnecting the DRAC module and connecting the 2000 ECM speedo output
wire (dk green/white from red #50) directly to the blue/black 1992 speedo wire that was plugged into the
DRAC module. Speedo works. Might as well try the cruise now. Jumped the dk green/white to red/white in
the DRAC module plug. Cruise works too. Wow. Easy. All connections made sitting in the passenger seat. The
only wiring that I had to do under the drivers side dash was to connect the OBDll port. So, long story short -
removed and discarded the 1992 ECM and DRAC module and make virtually all the harness interface
connections right there behind the glove box.
NOTE: I did not do anything about the rear anti-lock brake system because I believe that GM swiped it from
Fred Flintstones car. I intend on removing it completely. If I was to chase it, there is an output wire from the
2000 ECM to deal with it. (yellow/black 128k output from red #49) this should also be able to be connected
at the DRAC module plug.
Again, thank you Brendan Patten/LT1SWAP.COM, without your info I would not have even attempted
this swap. Nice work!

 

[618 Syndicate]

The cut and paste format you used makes this post unreadable.

 

[oldcarbguy]

The cut and paste format you used makes this post unreadable.

Oops, sorry, thought I might be able to help some normal folks by writing/posting that. Yes, I can see that it came out double line spaced. Funny thing is, I can read it. Un-readable like that? Something I have found over the years is that you just can't please everyone. 618 syndicate, you are proof of that.

 

[618 Syndicate]

Oops, sorry, thought I might be able to help some normal folks by writing/posting that. Yes, I can see that it came out double line spaced. Funny thing is, I can read it. Un-readable like that? Something I have found over the years is that you just can't please everyone. 618 syndicate, you are proof of that.

A) Don't get butthurt over criticism, get better at what you're doing. If you're "trying to help normal folks" start by making your help accessible. You took the time to share the information, why not do so in a fashion that is helpful?
B) Double spaced would be fine, this is what it looks like for "normal folks":

You must be registered for see images attach

Perhaps unreadable is too strong, but it's certainly not helpful.

 

[D-Day]

1992 K1500 LS swap information
The recipient of the swap is a 1992 GMC K1500 (4x4) 5.7L, 700R4/4L60 trans, 241C transfer case, regular cab shortbox
The donor truck was a 2000 Silverado 1500 (4x4) 5.3/LM7, 4L60E trans, 246 transfer case
This write up is a description of what was done and what I chose to use for this swap. There are many other ways to
arrive at the same conclusion. This is just what I did and some of what I found out along the way. I do have a
mechanical service background but this is the first LS swap that I have done.
I did my own wiring harness modifications using LT1SWAP info all way. The information on that site made this swap
plenty do-able by a regular ham-n-egger like me. As stated, just be patient, use some common sense and believe what
he says. It is right and it works. I admittedly do have some wiring harness assembly background but nothing like
this 160 pin GM ECM harness. It was a bit intimidating at first, to be sure. I just figured why not give it a try? I might
learn something and if I screw it up I can still buy one. I am glad I did it, I know a little more about things now.
I swapped the fuel pump to the later year, higher pressure type. I used Evil Energy braided hose and #6 AN fittings
for the feed and return lines. This line seemed to go together nicely and when pressure tested had no leaks
anywhere. So far a thumbs up on this line. NOTE: The 2000 lm7 has fuel feed and return lines so the Corvette
fuel regulator/filter everyone talks about was not needed
I deleted the EGR system - bought the commercially available block off plates.
I used ICT Billet motor mount plates which utilize the stock 1992 steel clamshells. The plates were advertised to be
clearance cut for the raised portion of the steel clamshells. They were not. They do have an area machined out but
certainly not for this application. Still not a big deal. I cut the raised portion out of my clamshells. I positioned the
clamshells the same distance from the bell housing mating surface as the 5.7L they were taken from - thus keeping
the transmission/driveline in the same place. When placed in that position, I had to do some minor grinding on the
clamshells to clear some bolt bosses in the block. I DID NOT use the 3/16" gusset bar mounting plates that were
between the clamshells and the 5.7L block. (I called ICT to verify this)
I used the 2000 alternator, power steering pump, hoses, and bracket assembly. The power steering hoses transferred
easily with just a small amount of bending involved.
The 1992 241C 27 spline transfer case (which I wanted to use) bolted right up to the 27 spline 4L60E from the 2000
Silverado 4x4 4L60E transmission. I used the 2000 transmission to transfer case adapter housing - I don't think it
matters which one gets used. And yes, it does require a gasket between the transfer case and adapter housing. What I
found is there are 241C transfer cases with the larger 32 spline input shafts. I am not 100% sure but I think
these are to mate up with the heavier 4L80E transmissions. In other words, make sure about the spline count/shaft
sizes when choosing your components.
I chose not to use the 2000 neutral safety/range switch. I used the 1992 neutral safety switch and the 1992 purple
starter wire. At the time I hoped that I would not not regret this choice. I did it figuring there would be less wiring
conversion for the cruise control and other possible dash wiring concerns. I figured that if it all works now why
mess with it? NOTE: The TCC wire is present in the 1992 wiring harness- it's the purple wire in the 4 wire plug
connected to the 700R4, connect this wire to purple wire from #33 Blue
I had to modify (shorten 1") the 1992 transmission shifter linkage (frame to trans) to allow for the longer shift post
on the 2000 4L60E transmission.
The 2000 Silverado (4x4) VSS wiring was not in the main ECM harness. The VSS wiring that was used by the 2000
truck was in it's own separate harness which was routed from the transfer case to one of the ECM fuse block plugs
via the left frame rail. The 2000 transfer case appears to have at least 2 VSS sensors. There is a twisted wire VSS
wire pair in the main harness leading straight to the ECM but it is apparently used for 2 wheel drive applications only?
The plug on the end of that wire set was capped. I chose to use that 2 wire set figuring the 241C transfer case has only
one VSS and those wires led directly to the ECM positions shown in the LT1SWAP ECM pinout. I spliced the 1992 VSS
plug into it to mate with the 1992 transfer case sensor.
I used the 1992 15 pin white wiring connector plug located behind the 1992 glove box as a junction point for a lot of
the wiring between the 1992 dash and the 2000 ECM. This plug and wiring notes are shown in LT1SWAP.com. Use the
facebook prompt and scroll thru the posts to find it. (It is toward the end of the posts.) This was a very valuable find
for me. I did not cut off any of the "extra wires" because I was not sure what extra was.
NOTE: The DRAC module is also located behind the glove box. I will be referencing that later on.
I used the 1992 battery location, +/- cables and associated power cables to the 1992 junction block on the firewall. I
also kept and re-used the 1992 bell housing bolt mounted tin heat shield to protect the wiring in the starter area. I
re-routed the LS crank sensor wiring through this heat shield also.
I used the 1992 fuel pump relay and associated wiring on the firewall but used the 2000 ECM fuel pump relay wire
to trigger it. Cut the 1992 green/white wire, connect the 2000 green/white to it. (from 2000 ECM red #9)
I used the 2000 alternator exiter wire and plug. I don't care if I don't have an "alt" idiot light.
I used the 1992 temperature sender (single green wire in left 1992 head) and put it in the passenger side LS head
using an adapter fitting. After I had the motor in place I found that I should have drilled and tapped the head to
accept the 1992 temp sensor (3/8"NPT) I was on the verge of putting it in the water pump but after some test
fitting I found that there actually was room for it using the short adapter fitting available for this. It does fit but
ends up mighty close to the transmission tunnel/firewall.
I used the 1992 3 pin oil pressure sender and associated 1992 wiring. Thread adapter required.
I used the 2000 silverado exhaust manifolds. They fit nicely. No issues whatsoever.
I used the 2000 Silverado "Y" pipe with converters intact (for noise reduction only) The front 02 sensors have
plenty of clearance. I did not use the rear sensors. I used the bolt together flange at the end of the pipe and
enough pipe to meet up with the 1992 exhaust pipe. Cut and weld here - a bit of fiddling and hammer welding,
2 1/2" pipe to 3" pipe.
I used ICT Billet AC compressor mounts - They put the compressor in roughly the same place as the 1992 location.
I did not disconnect the hoses, just set the compressor off to the side until the motor was in place, then bolted the
compressor in place - some "massaging " of the lines is needed but nothing too drastic. With this setup a 110 1/2"
belt fit well.
The 1992 K1500 does not have 4 LOW light. A a switch could be added to address this. Set it up so that when
shifted to 4 LOW, gray/black from #16 red goes to ground
I chose to use the 1992 radiator. It has a 5/8" heater hose connection on the right side tank which I used for
the LS steam port. I made my own adapter fitting. The 2000 radiator hoses fit perfectly.
I used the stock 1992 transmission cooler lines. Had to transfer the line fittings from the 700R4 to the 4L60E.
The lines fit pretty well, just a little adjusting required.
I chose to use electric fans so I cannot confirm the stock water pump fan fit but it sure looks like it would
fit just fine.
I used the 2000 throttle cable- just a tiny bit of re-shaping of the plastic to fit the 1992 square hole
I left the 1992 cruise control module in place but installed the 2000 cable in it. Easy, squeeze the tangs, pull
out the cable, un hook it from the ribbon, replace it with the 2000 cable.
After deleting the VATS and re-setting the factory tach setting using an HP tuner - The factory tach was
reading about 1/2 the actual rpm. There is a tach setting in the tuner that showed a #6. Changing that to #3
corrected the tach.	The truck runs and drives now.
At this point I was still unsure about the speedo and cruise control electrical connections. In all my searching
I could not find any convincing evidence about how to deal with the DRAC module etc. Lots of internet chaos
about that. I decided to try just disconnecting the DRAC module and connecting the 2000 ECM speedo output
wire (dk green/white from red #50) directly to the blue/black 1992 speedo wire that was plugged into the
DRAC module. Speedo works. Might as well try the cruise now. Jumped the dk green/white to red/white in
the DRAC module plug. Cruise works too. Wow. Easy. All connections made sitting in the passenger seat. The
only wiring that I had to do under the drivers side dash was to connect the OBDll port. So, long story short -
removed and discarded the 1992 ECM and DRAC module and make virtually all the harness interface
connections right there behind the glove box.
NOTE: I did not do anything about the rear anti-lock brake system because I believe that GM swiped it from
Fred Flintstones car. I intend on removing it completely. If I was to chase it, there is an output wire from the
2000 ECM to deal with it. (yellow/black 128k output from red #49) this should also be able to be connected
at the DRAC module plug.
Again, thank you Brendan Patten/LT1SWAP.COM, without your info I would not have even attempted
this swap. Nice work!

Thanks for all this information. You answere alot of my questions that I'm working on with my LS swap. I'm posting mine as I go with pictures. I bipassed the DRAC unit wiring becuase what I read about the pulses per minute where the same. I can tell you how and if it works out?