Quick and dirty LS swapped C2500

jfg455 said:

Here is the factory AC unit mounted to the LS motor. Short version of how to do it: cut off the single leg that hangs down, Use 1 bolt into the front of the passengers side head, Make a bracket that supports it front to back as well as up and down, swap to a 2720mm belt length, move the idler pulley over to the inside bolt for the alternator and you can use the C/K tensioner.

I also have the intake on it, made plugs for the EGR and EVAP purge solenoid holes. The fuel lines are just the end of the LS lines adapted to the steel TBI lines that come up in the same spot.

Here is what I have left:
-replace fuel pump with high pressure unit
-put radiator back in and hook up lines
-shorten drive shaft
-Air intake
-wiring
-exhaust (I found a Corsa stainless system for an escalade on CL for $200)

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Why are you doing this/what are you doing? Are you mounting the 1992 compressor to the LS motor? Or are you raising the LS compressor to fit in the 1992 truck?

Flipper_1938 said:

Why are you doing this/what are you doing? Are you mounting the 1992 compressor to the LS motor? Or are you raising the LS compressor to fit in the 1992 truck?

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SO the LS style AC compressor (all of them IE: truck, F body or vette) mounts low on the passengers side of the motor. On most older muscle car frames and 2wd truck frame the only way to make the factory LS compressor work is to heavily notch the frame. You also cannot use the 1" set back mount plates so then you have to move the mounts back on the frame etc etc.

What I am doing here is using the 92 pancake AC compressor and SBC (or 4.3 v6) mount and attaching it to the front of the LS block using 1 of the existing holes in the mount and 1 existing hole in the head. The belt spacing is perfect to line up with the truck accessories on the LS motor. You remove the LS tensioner and use the 92 tensioner that mounts to the AC bracket. You do have to add the rear bracing bars IE: 1 down to stop the bracket from rotating and 1 to the rear to stop flex. Doing it this way I can use my existing AC lines as well. Very easy way to keep the AC and if you need a high mount AC in a street rod then this is cheap and easy. Clear as mud?[

Here is the stock LQ4 AC compressor location, tensioner and head bolt holes...



And here is the bare bracket from the front. Cut off the lower leg at the line, use one of the 2 existing holes just above the cut line. I used the right hole in the right upper LS head hole...

Nice swap! They are so easy to make a lot of power.

Great info, I have to use up my LTs and get into the 6.0 swaps, already have a 2000 6.0 here to use.
When you get the PCM reprogrammed is there anything you get turned off other than the rear O2 sensors, EVAP, VATS, and maybe EGR? Who do you have do the reprogramming and retune for the cam swap?

drptop70ss said:

Great info, I have to use up my LTs and get into the 6.0 swaps, already have a 2000 6.0 here to use.
When you get the PCM reprogrammed is there anything you get turned off other than the rear O2 sensors, EVAP, VATS, and maybe EGR? Who do you have do the reprogramming and retune for the cam swap?

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I just bought HP Tuners and a good friend of mine is better at tuning than I am. You hit most of the stuff you turn off for DTC's. Depends on what you are using for a trans too. If you are using say a TH350 or TH400 then you can shut off the trans DTC's as well. Then there are things you can do like if it drive by wire you can turn off the torque management functions so the throttle blade opens faster from a stop. You can reduce the amount of knock retard perimeters so you don't lose as much power if you get a batch of bad gas. Add fuel or timing etc.

As far as the cam swap there isn't much to retune for it. Mostly just rev limiter and watch the air fuel ratios to see if it is still on target. You can then play with more timing or fuel depending on what the motor now wants.

I'd best get crack a lackin as I just sold my daily driver...the temps are heading down and all I have to commute with is my bike...Lol[cl

So I finally got a day off so I knocked out the exhaust and driveshaft. I scored a pile of new take off GM parts off Craigslist. 2 duramax intercoolers, a stock Tahoe exhaust (they are 3" and 409 stainless) and this GM performance parts stainless exhaust. It is made by Corsa and is 304 stainless. All of the stuff was $400. I chopped up the GM performance exhaust and used bits of another to make it all fit.

Then I shortened the driveshaft and added the TH400 yoke that also fits the 4L80E

And because I'm really cheap I converted a passengers side battery mount to fit the drivers side so I can run a Silverado air intake which mounts where the passengers side battery usually sits. I could have bought one but they are $78. Besides it was only about 20 minutes of my time to convert.

Wow! JFG, i would like to see what would result if you and your mechanical skills hooked up with one of the guys on this board with their bodywork skills. [cl

earthman said:

Wow! JFG, i would like to see what would result if you and your mechanical skills hooked up with one of the guys on this board with their bodywork skills. [cl

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I'm really hoping to get this running before my A.D.D. kicks in and I wander away onto another project...[cl


I've never had the patience to do body work...I fully understand the process but can't commit the time it takes to do it correctly... my dad used to have me spray the MG's he restored. He was a 1 track minded person and could get the panels in great shape for paint but for some reason he couldn't get the paint or primer to lay out the way I could. He used to say having me shoot them saved him tons of hours of labor to fix them...

And today I started the wiring. 1st up was to remove all the stuff I wasn't using from the old harness IE: injector wires, MAP wires, throttle body wires etch. Then I lay the new harness on the engine and attach the connectors where they go. I will start removing stuff I don't need like rear O2 sensors wires, AC wires, EVAP wires, EGR wires etch. Then I will integrate the 2 harnesses.

At some point I'm gonna have to pick your brain to put one of these motors in a old turd and build a sleeper out of it! [ddd

So is this thing driving yet? [dr

05snopro440 said:

So is this thing driving yet? [dr

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Lol can't a guy go on vacation around here?? Seriously, I just got home an hour ago from a cruise...7 days from NY to Nassau... along with 25 Ft seas, 45 knot winds![cl lucky I found a bar on ship selling pitchers of Newcastle for $16! The $10 rum and cokes were going to sink me with the ship!!

I work tomorrow and have 2 court cases on Tuesday but then I should be able to get the radiator in, fuel pump swapped and get going on the wiring....[P

So I got a little time to dig into the wiring a little more today. I opened up the factory LS harness and deleted the circuits I won't be using EG: EGR, AC clutch and pressure switch, oil level sensor, EVAP solenoid, low coolant sensor, transfer case circuits, and rear O2 sensors. As you take wires out I always suggest taping the harness back up to keep it neat. Also the connectors you are keeping will stay in place where they need to be.



These 12 pink wires are all "IGN 1" circuits or hot in run, crank, and start positions. They will get bundled into 4 sets of 3 circuits each going to a fuse. I will add connectors to the oil pressure circuits and the speed sensor circuits so I can splice the truck side to the pcm harness. There are 2 B+ circuits that will go to the hot junction block.

jfg455 said:

So I got a little time to dig into the wiring a little more today. I opened up the factory LS harness and deleted the circuits I won't be using EG: EGR, AC clutch and pressure switch, oil level sensor, EVAP solenoid, low coolant sensor, transfer case circuits, and rear O2 sensors. As you take wires out I always suggest taping the harness back up to keep it neat. Also the connectors you are keeping will stay in place where they need to be.



These 12 pink wires are all "IGN 1" circuits or hot in run, crank, and start positions. They will get bundled into 4 sets of 3 circuits each going to a fuse. I will add connectors to the oil pressure circuits and the speed sensor circuits so I can splice the truck side to the pcm harness. There are 2 B+ circuits that will go to the hot junction block.

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Looks like you're making good progress on the wiring! I can't wait to see the finished product of this, it's a super cool build!

I want to do a year-round daily using an older body with a modern LS and 4WD chassis underneath! One day...

05snopro440 said:

I want to do a year-round daily using an older body with a modern LS and 4WD chassis underneath! One day...

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My thought was a glass bodied 33 - 34 ford 3 window, full fenders, build the chassis out of 409 stainless steel, use 304 stainless for brake, trans cooler and fuel lines, LS engine, 4L60E trans, stainless hair pins etch and run it year round. Wouldn't people just gnash their teeth and pull their hair out to see it cruising through a snow storm![cl

jfg455 said:

My thought was a glass bodied 33 - 34 ford 3 window, full fenders, build the chassis out of 409 stainless steel, use 304 stainless for brake, trans cooler and fuel lines, LS engine, 4L60E trans, stainless hair pins etch and run it year round. Wouldn't people just gnash their teeth and pull their hair out to see it cruising through a snow storm![cl

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Hmmm... That would work... Could also make it AWD...