Green95Hoes LQ4 with NV4500 Conversion. Jam packed with info.

[Green95Hoe]

Intake Manifold:

Since my engine was missing parts, I had to look into what I needed for the intake. I didn’t have the plastic cover or the brackets. I saw one on a 5.3 in the salvage yard so I grabbed the cover and the little mount plate that bolts onto the intake. This should do for now until I decide whether I want the Vortec Max 3 piece covers or not. Note: the 3 piece ones need the mounting studs on the valve covers) My engine had a drive by wire throttle body. I chose to avoid this route as mounting the pedal is a pain and you have to alter the bend of the pedal to fit in the OBS. Drive by wire makes me nervous too. I like my foot physically connected to my intake. The salvage yard had a 5.3 with the cable throttle body. I grabbed that and the little bracket that goes on top of the intake to connect the cable. Cant forget that. I also learned that I needed a 96-99 style throttle cable. Grabbed one at the yard as well. My intake had a plug in the back where a brake booster would connect. The donor truck must have had hydroboost assist brakes. Since my truck needed a connection to the brake booster, I had to get the adapter. This was one of those items that I bought online before realizing they were so plentiful at the bone yard. No big deal, I only paid 5 bucks for the nipple. Before I forget, there was another difference between the DBC and DBW throttle bodies. The DBW unit on my LQ4 had a vacuum line coming off the top of the throttle body that went to the valve cover. Apparently the early throttle bodies had this line right on the throttle body. Later models they moved the line right onto the intake manifold and deleted it completely from the throttle body. Since I was swapping old onto new, I capped off the nipple coming off the throttle body. I also bent it down and out of the way. I should also note that there is a small hose nipple on top of the LSX intake. It comes from the factory with a break off tab in place so if you want to use the nipple, you will have to break off the tab. This can be a vacuum source for things like the AC diverter valve dashpot, carbon canister, evap component, or in my case, a mechanical vacuum gauge. I did some research on the steam lines. It seems that a line must come off the radiator (not the overflow line) and tie into the steam lines. The valve cover plumbing must be used, but the connection to the throttle body is not required. Well to me anyway. It is supposed to help with throttle bodies freezing in the winter. I chose to plug off both ports under the throttle body for now. If I have throttle issues later. It will take a mere minute to re-route the lines through the throttle body. I connected my plumbing directly to the extra port on the radiator. To make the change in hose size, I went to Home Depot and bought some brass fittings. A hose barb on each end for the proper hose size and a Coupler in the middle.

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[Green95Hoe]

Sensors and stuff:

This area got really confusing fast too. Here's the story. You have an oil pressure sender in the same area as the SBC. This is not needed by the ECM in any way to run the engine. Its sole purpose is to run the oil pressure gauge on the dash. There are 3 wires here. One is power, one is ground and the last is signal. I presume this sensor gets 12volts when the key is on and thus triggers the oil light on the dash. Once the truck is running, the pressure increases and the light goes off. OK so that being said the idea is to run the original SBC oil pressure sender in that location after removing the existing sensor. I couldn’t find an answer about just splicing the wires into the sensor in the LSX. Everyone is running their old sender so I decided to do the same. You will need an adapter to make this connection. Remember when I said everything was metric? Most people talk about the ones from S&P performance. They cost double because they are chrome. Auto Meter makes one for half the price so I went that route. There are also 2 other places you can steal oil pressure from. There is a plugged boss in the lower block an some have used the coolant line block off plate that has threads for running a sender. IM just using the one behind the intake because that’s where my factory harness plug is already. Use the other locations if you decide to add a second mechanical gauge.

You have a coolant temp sender on the passenger side of the engine. Don’t take this out unless its malfunctioning. Some have 2 wire units and some have 3 wire. The third wire (the one below the two that are side by side) can be wired directly to your dash gauge. I have heard there are discrepancies between the actual temp and indicated temp. If you only had a 2 wire sensor there, you can change to the 3. The part number is TX111 and the pigtail is S619. (Or use your former TPS plug if it’s a round style) I have a second mechanical water temp sensor. I could have put it anywhere really. Turns out GM was really good with giving us options. If you look on the drivers side in the back of the head, there should be a bung there. Again there is an adapter for metric to SAE on the S&P site, but the Autometer one was cheaper. This is probably a better place to put your dash gauge connection. Some have said it gets in the way of the spark plug wire. But it wasn’t an issue for me. I should note that I had to slightly drill out the adapter to fit the aftermarket probe inside for my added mechanical gauge.

My SBC had oil cooler lines. The new LSX engines don’t need this as much as the old engine so you can bypass it. Most do anyway. My engine used to have lines so I needed to cap off the 2 holes. There are 2 styles of block off plates from GM. One is just flat and is a basic block off. The other has a threaded boss for adding a sensor. It can be drilled and tapped for larger sensors. I believe they come threaded but not drilled all the way through. Should you want to add a sensor, just drill it out. There was a GM part for the cover, but I soon learned there was a separate number for the gasket and then another for the bolts. It was cheaper to buy the kit on ebay.

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[Green95Hoe]

Most people converting to LSX will opt for the Electric Fans. Its more efficient at cooling and less drag on the engine means more power. I had already done an Efan conversion years ago with a custom wiring harness and Rheostat to turn the system on. I could have tied it into my ECM but for now I am leaving it alone. Once I get this all dialed in setup electronics wise, ill upgrade the fan system if necessary

Regarding AC. Initially I was going to just abandon it, then when I got to the 11th hour of the install, I decided to just do it right. I should have sprung for the brackets initially. Prob is they were 300 bucks. I chose the dirty dingo ones as I had already done business with them for my motor mounts. I also didn’t have the hardware to mount my tensioner pully so buying their bracket not only gave me a mount for the compressor, but it included the pully. I didn’t even have to split the pressure lines off the compressor either. There were a few catches though. I found that the belt rode just along the edge of the tensioner pulley. To remedy this, I placed a 1/8” shim behind the tensioner pulley. You wont be able to go any more than 1/8” because the pin on the back of the tensioner must stay in the provided hole. The next issue was belt size. The one they sent me had an effective length of 105.77. I’m guessing that since I went with the 145amp alternator, I needed a larger belt. Gates K061066 was about an inch longer and worked great. Also Dayco 5061065 should work. There was even a little extra room to go longer so I think any 107” belt would work too.

 

[Green95Hoe]

Fuel and Exhaust:

Exhaust is pretty self explanatory. I had a custom setup already so to make the connection to the piping I just had to get the truck to my local pipe guy and have him custom bend the intermediate pipe. I also had him weld in the bungs for the O2 sensors and just for the hell of it, an extra bung for a wide band in case I want to tune more accurately later. Earlier I mentioned about the debacle with the flanges. Make sure you have those first if you are connecting to stock manifolds.

Fuel pump and lines. If you have a TBI injection system, the stock pump will not flow enough pressure. The 96-99 Vortec pumps work and a few others as well. I stuck with an AC Delco pump. Since I have a Tahoe, I needed to drop the tank. Not a big deal since I did that 3 years ago to change my sender. This turned out to be another process. You see I had upgraded my fuel pump years ago for the TBI, but it still wasn’t enough to pump the SFI injection on the LSX. The issue I ran into was that I had to change the plug to run the Walbro. I must have discarded the old smaller GM style fuel pump connector. GM has a part number for the pigtail (25117765) or Standard Motor Products Part # S722. Both were available online but I didn’t want to wait. I wanted the tank back up. Rain was coming and keeping the tank in my garage was fuming us out. Some research led to Airtex #WH3000. This is the fuel pump 4 wire connector that goes in between the upper and lower portions of the pump on 96-99 pumps. This wasn’t supposed to be compatible with my truck because the upper plug was different. It didn’t matter as long as the actual pump plug was the same. I matched it up in store (Auto Zone) and bought it over the counter. Then just cut out the pigtail piece I needed and spliced it into my existing setup. Then put the tank back up. I should note that the pump I had in there had a rather dirty filter. There wasn’t a sock on the bottom of the pump but there was one on the bottom of the plastic outer can. I made sure to install a sock inside the can. Factory pumps have the sock, most aftermarkets don’t, but since my tank seems to be prone to junk getting in, I will run the sock inside the can. If your factory lines are still solid, you can just get the adapters to make the connection to the fuel rails at the engine. My lines were a pish posh of repairs and rubber tubing everywhere that may or may not have been fuel injection hose. Also my fuel filter was rusted to the lines. Some engines have a returnless setup where you only need to run one fuel line to the engine. The return line comes off the back of the corvette fuel filter. My system had dual rail and it would have been simple to connect to the engine if my lines were still solid. They weren’t. I was going to run braided line the whole way but the fancy fuel injection connectors were 20 bucks a piece. Between lines, fittings and filter it would have cost me near 200 to do this. I ran rubber FI hose from a clamped connection at the fuel pump down to a 60” straight steel line which had rubber on the other end running up to a clamped connection at the fuel rail. (Quick connects at the fuel rail) I ran solid line for the straight away and spliced fuel injecton hose to make the connection between the center solid line and the repair kit plumbing. There is no difference in fuel filters with regard to the TBI injection pressures and the SFI injection pressures so you can use a stock filter part number. I went with the Delco filter as its stainless and I don’t have to worry about threads rusting together later on. As for making the connection to the fuel filer… Advance Auto parts had an elbow with 3/8” line that connected to the filter. I cut the elbow off so I just had a 3” piece that threaded onto the filter. To this I clamped the FI hose that ran up to the pump. On the other end I did something different. Adavance had a kit that was a 16” piece of 3/8” tubing and a union. The threaded end went into the pump, the union connected to the 60” piece of 3/8” I had bought prior. FI hose is expensive so I made sure to fit up the metal lines where I wanted them and then take measurements for the length of hose I would need. The feed line is 3/8” and the return is 5/16”. All clamped connections were with double fuel injection hose clamps.

 

[Green95Hoe]

Tuning:

This is one dept I chose to leave to a professional. Luckily for me, our founder Mike (Tharf) lives near me and was able to do all my tuning. He flashed my PCM initially to get me running so I could get the truck down to the exhaust shop and add in my 02's. There were a lot of things to be changed. Remove Vats, remove rear O2, change tach pulse, raise idle slightly. Once I log some miles, I will have him make some small changes. I can't say enough great stuff about his work and I have personally seen him in action at the shop. Thanks again Mike at MJEngineering. Without your support I wouldn't have taken on this project. Your knowledge and experience gave me the nudge I needed to make the right decision going LSX.

 

[Green95Hoe]

Final Loose Ends:

-I needed to select an intake tube. After reviewing some threads online, the Hummer H2 tube seemed to be the best option. I ordered that up. The blue couplers didnt fit my theme though. I will start looking for red or black ones.
-Engine covers: different covers need the matching brackets to connect. I am going to run the 5.3 cover for now because that’s what I have the brackets for. In the meantime I am going to look for the 3 piece 6000 or Vortec Max covers (GM #12597908 ($17) driver, 12598332 ($19) center, and 12574573 ($30) left)
-Most trucks run the heater core lines right to the two bungs sticking out of the firewall. My truck had some plastic valve with a little vacuum actuated dashpot on the side. A little digging turned up that this was a diverter valve used in the SUV trucks. Supposedly it cuts off the flow of hot water when using the AC system. I chose to left this in place. The small vacuum line source is atop the intake as I identified in the “Intake” section.
-Alternator: since my engine did not come with one, I needed to source one. At first I wanted to use my SBC alternator as it was a higher output model. I couldn’t confirm if this was a possibility so I decided to run with a new LSX unit. Nothing was available in a junkyard but if I knew then what I know now, I would have pulled a junk one to use as a core charge when purchasing a new one. stock is 105amp but there is a 145amp version of the new alternators available (KG3 Option). Rock Auto had the KG3 for 110 which was the best price new and didn’t require a core like my local parts place. I took my chances with a used KG3 from Ebay as it was only 40 bucks. At least this way I will have a core when I need to replace it someday. Supposedly the fan belts are different sizes with the different alternators. I pretty much confirmed this when my AC bracket arrived. You will need a belt about an inch longer for the larger alternator.

 

[Green95Hoe]

Parts List information for my swap: TOTAL $2211.00

LQ4 6.0 from 03 GMC Yukon Denali XL with 103K from Evertetts Auto Parts for $650
“How to Swap GM LS Based Engines into almost anything” book from Barnes and Noble $25
Pilot Bushing SKF 6302VSP43 (also #12557583) Ebay $25
AC Delco Fuel Pump EP381 Ebay $50
Dirty Dingo Motor Mount Offset Plates $100
Coolant temp sensor adapter from speedway motors #1822277 $10
Oil Pressure sending unit adapter #1822268 from speedway motors for $11
Sachs Flywheel for 6.0 from O'Reilly #NFW1050 for $55
Flywheel bolts (6) from GMpartsgiant.com 11569956 $15
Nipple for brake booster connection to intake 12559760 from gmpartsgiant.com for $5
Oil Cooler Block Off Plate Kit w/ Gaskets and Bolts from Ebay for $16
Exhaust Manifold bolts from Ebay - $17
Exhaust Manifold gaskets from Rock Auto GM #12617944 - $18
Two Oxygen Sensors from Rock Auto #Bosch Part #15703 - $50
KG3 Option (145amp) Alternator from Ebay for $56
Standalone Harness from Current Performance (no fans and no tranny control) - $550
Spark Plug - TR55 from Rock Auto - $12
3 Wire Coolant Temp Sender (Standard Motor Products #TX111) from Rock Auto - $19
3 Wire Coolant Temp Sender Pigtail (Standard Motor Products #S619) from Rock Auto - $14
Oil Filter Wix 51522 (Tall Filter) from Rock Auto - $5
Idler Pulley from Rock Auto - Dorman 419602 - $6
Intake Tube IK-701 (Hummer H2) from Ebay - $68
Quick connect 5/16 and 3/8" for Fuel Rails from Advance Auto Parts - $24
LS R4 AC Compressor Bracket from Dirty Dingo Motorsports with belt - $320
Everetts misc items. Cost was $90 for the 2 buckets filled with the following:
Radiator Hoses and clamps
Accelerator Cable from 96 truck
Drive by Cable throttle body
OBS Drivers Side Battery Tray
OBS Drivers Side Windshield Fluid bottle to go under Battery
5.3 Engine Top Plastic Cover/Shroud
Bracket to mount above Cover/Shroud
Bracket for Throttle Cable
ECM from 2000 Silverado Serv #09354896
Starter and both mounting bolts
Power Steering Pump and Pully
Bracket to mount Power Steering Pump and Alternator


Exluded cost of Tune and Exhaust rework.
Also there are a few more things to add. I will throw those in tonite when I get home. Also need to add some pics to this. Most of them are still on my camera.

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[Green95Hoe]

So if you wanted to know how one gets an engine into a truck lifted as high as mine. Check this out.
My dad brought home the boring rig tripod from his work. He is standing under so you can see how high the engine has to go to clear the radiator support.

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[low4x4]

you did a great job.....can't wait to see a supercharger on it...... someday

 

[Green95Hoe]

Thanks Barry, maybe someday. House first though.

Got it back tonite. Sounds great. Except for the fact that my junkyard alternator started squealing on the way home. Ill swap that out tomorrow and then get some video up.
The exhaust note is different because I have 12" resonators up front and single chambers out back. Now that its all said and done, the one thing that stands out more than anything else is the different sound of the starter when I turn the key.