5.3 to 6.0 swap!

07sierraclassic

07sierraclassic

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Mar 11, 2012
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Buckley, WA
Hopefully if i do this right a mod will sticky it for other members to use. I'm currently in the process of swapping my L59 (flex fuel 5.3) to an LQ4 6.0. So far, I've gotten the whole wiring harness disconnected and intake manifold removed. Plan to use the intake manifold and throttle body from the 6.0, fuel rail and injectors front the 5.3 (because of flex fuel). Has gone really well so far. Plan to pull 5.3 out of the truck tomorrow morning and have 6.0 in by tomorrow night. Also using 5.3 wiring harness as my injectors have different connectors than the 6.0 as my original engine has a flex fuel system.

Truck is a 2007 GMC Sierra 1500 Z71 CLASSIC

Post-6.0 swap edits: We ended up pulling the radiator, fans, grille, passenger side wheel and inner fender for ease of removal/installation and the inner fender for accessibility. These engines sit so far into the firewall that its necessary to pull the radiator/fans to get the engine out and back in without fuckin shit up. Also removed the good and intake manifold, as well as the exhaust manifolds because they were easier to take off once the engine was out. My biggest piece of advice would be use WD40 on ANYTHING that you think would be difficult, because it will be. Most of the time spent on this was due to PITA nuts/bolts, a lot of that could be because of the excessive moisture here in WA But either way...

When we were ready to put the 6.0 in, we removed the drivers side exhaust manifold to clear the steering shaft (my engine came from the junkyard complete minus accessories) and from there it was literally just piecing everything back together. Used 5.3 exhaust, throttle body (same P/N on the 6.0 piece anyways) fuel rails and injectors (flex fuel, though I've heard you can use the 6.0 stuff, I went this route for ease of installation/time purposes. I don't run ethanol anyways). The only things I had to change were the oil pressure sender to match the plug I had on my existing harness, and I changed out my starter to the 6.0 (5.3-6.0 starters have different part numbers, starter motor appears to be larger on the 6.0 starter). Truck is running in HP Tuners using the stock 5.3 tune with tr cylinder volume changed for the 6.0.

Overall the swap is really straightforward, just takes time and perseverance to finish, as you'll find more than enough bolts you can only get an 1/8th of a turn on (bell housing bolts....) but it is SO worth the time if you have a 4.8-5.3.
 
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I literally just finished up my swap to an lq9 yesterday. I had to reuse my 5.3 intake since my throttle body wouldnt work on the 6.0 the only other small thing was a plug for the intake since my new motor didnt have egr. Its really not a hard swap at all. Goodluck!
 
Sounds great, post some pics to keep us simple minded folk entertained.

Make sure your tune is for flex fuel injectors as they have a bigger flow rate then 6.0 injectors
 
as soon as you ad info, I can add it as a sticky. We will clean it up as well. Try to put everything in your first post.
 
Be very thorough with your pics and explanation and you may have successfully written a tech article as well :crazy:.
 
Awesome! Will the 5.3L stuff flow enough fuel for a built N/A 6.0L? E85 is pretty much street legal alcohol.
 
Yeah everything except the rails and injectors is identical between the two. Have all the accessories off the 5.3, now the fun stuff. Have to disconnect the exhaust from the manifolds (absolute pain in the ass), bell housing and torque converter and it's ready to come out. Can't believe how much of a PITA it is to simply remove the starter or just to get the harness disconnected and out of the way. These engines sit way farther into the firewall or under the cowl compared to like my Obs. Oh well, almost there. We also took the radiator and fans out for extra room. How do you post pics from tapatalk?
 
Hit reply, then hit the camera button next to discard, choose where to upload from, pick photo, then choose tapatalk hosted.
 
Are the starters from the 5.3 to 6.0 different?? All done and the motherfucker won't barely turn over. So frustrating. Battery is new btw

EDIT: it appears as if they are in fact different, starter from the 5.3 doesn't have the balls to turn my LQ4 over, and they have different part numbers.
 
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07sierraclassic said:
Are the starters from the 5.3 to 6.0 different?? All done and the motherfucker won't barely turn over. So frustrating. Battery is new btw

EDIT: it appears as if they are in fact different, starter from the 5.3 doesn't have the balls to turn my LQ4 over, and they have different part numbers.
Click to expand...

Hmmmm. I've never heard of having to change the starter. I used my 5.3 starter on my lq9 swap, and it has more compression than a lq4 does .

Sent from my HTC VLE_U using Tapatalk 2
 
sevy2ava.jpg
almost completely done at this point.

ujabeqy5.jpg
the 5.3L that came out lol
 
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