Swapping a GEN 3 for a GEN 4
Thread Starter
Teching In
Joined: May 2019
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Swapping a GEN 3 for a GEN 4 Hello all, new guy here.
I have an 05 gmc Sierra with the gen 3, 5.3.
I have purchased an 08 aluminum block gen 4 5.3.
I know there are things to change, and I'm just looking for info that I am not sure of.
All help is greatly appreciated.
I will be deleting the DOD AND AFM stuff. Already have.
I am also deleting the knock sensors when the truck is dynoed and tuned. So I don't have to worry about extended harness and drilling block to move.
I have already swapped the crank for a 24x because it's a 58x that won't work with my computer.
My biggest concerns are the cam.
I know I have to extend the cam sensor wiring to move it to the front of the engine. I know that requires a new front cover.
My concerns are I already bought a cam for the gen 3 block BEFORE I found this gen 4, so can I still use the cam I already had custom ground?
What all do I have to change to do this? Just the timing set basically?
I have an 05 gmc Sierra with the gen 3, 5.3.
I have purchased an 08 aluminum block gen 4 5.3.
I know there are things to change, and I'm just looking for info that I am not sure of.
All help is greatly appreciated.
I will be deleting the DOD AND AFM stuff. Already have.
I am also deleting the knock sensors when the truck is dynoed and tuned. So I don't have to worry about extended harness and drilling block to move.
I have already swapped the crank for a 24x because it's a 58x that won't work with my computer.
My biggest concerns are the cam.
I know I have to extend the cam sensor wiring to move it to the front of the engine. I know that requires a new front cover.
My concerns are I already bought a cam for the gen 3 block BEFORE I found this gen 4, so can I still use the cam I already had custom ground?
What all do I have to change to do this? Just the timing set basically?
Last edited by Qwikslvr; May 9, 2019 at 10:11 PM. Reason: Title was wrong
Hello all, new guy here.
I have an 05 gmc Sierra with the gen 3, 5.3.
I have purchased an 08 aluminum block gen 4 5.3.
I know there are things to change, and I'm just looking for info that I am not sure of.
All help is greatly appreciated.
I will be deleting the DOD AND AFM stuff. Already have.
I am also deleting the knock sensors when the truck is dynoed and tuned. So I don't have to worry about extended harness and drilling block to move.
I have already swapped the crank for a 24x because it's a 58x that won't work with my computer.
My biggest concerns are the cam.
I know I have to extend the cam sensor wiring to move it to the front of the engine. I know that requires a new front cover.
My concerns are I already bought a cam for the gen 3 block BEFORE I found this gen 4, so can I still use the cam I already had custom ground?
What all do I have to change to do this? Just the timing set basically?
I have an 05 gmc Sierra with the gen 3, 5.3.
I have purchased an 08 aluminum block gen 4 5.3.
I know there are things to change, and I'm just looking for info that I am not sure of.
All help is greatly appreciated.
I will be deleting the DOD AND AFM stuff. Already have.
I am also deleting the knock sensors when the truck is dynoed and tuned. So I don't have to worry about extended harness and drilling block to move.
I have already swapped the crank for a 24x because it's a 58x that won't work with my computer.
My biggest concerns are the cam.
I know I have to extend the cam sensor wiring to move it to the front of the engine. I know that requires a new front cover.
My concerns are I already bought a cam for the gen 3 block BEFORE I found this gen 4, so can I still use the cam I already had custom ground?
What all do I have to change to do this? Just the timing set basically?
edit...Welcome to LS1Tech!
Thread Starter
Teching In
Joined: May 2019
Posts: 6
Likes: 0
Cam will work, as you stated, just change timing set. You purchase a 3 bolt camshaft? Yes different front cover with cam sensor. I do not recommend deleting knock sensors. Knock sensors allow you to find easy power with tune via timing, and still keep engine safe. I know guys do it, but that’s my opinion on the subject. Easy to keep them and use adaptor harness.
edit...Welcome to LS1Tech!
edit...Welcome to LS1Tech!
Its a gen 4 block, so the knock sensors go on the sides down behind the engine mounts. There is a machined round surface on each side, a little bigger than a quarter, with a threaded hole in the center. They go there. The engine should have them still on it if you bought it complete. Easy peasy.
Thread Starter
Teching In
Joined: May 2019
Posts: 6
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Its a gen 4 block, so the knock sensors go on the sides down behind the engine mounts. There is a machined round surface on each side, a little bigger than a quarter, with a threaded hole in the center. They go there. The engine should have them still on it if you bought it complete. Easy peasy.
No, they weren't on the engine. I looked at it briefly before taking it to machine shop for prep work, but I didn't see where there were any holes that would have had them. There were definitely not any "open" holes that I can remember. I guess I'll double check when I get it back from machine shop.
Thanks for all the help and info
TECH Senior Member
Joined: Jun 2016
Posts: 22,298
Likes: 3,619
From: Central Cal.
Just so nobody happening upon this thread blows a gasket, you are converting from a GEN III to a GEN IV, NOT LS3 to LS4.
LS3 is a Corvette/Camaro 6.2Lengine, and the LS4 is a front-drive 5.3L engine that will not fit any rear drive app.
LS3 is a Corvette/Camaro 6.2Lengine, and the LS4 is a front-drive 5.3L engine that will not fit any rear drive app.
Thread Starter
Teching In
Joined: May 2019
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Fixed. I really don't know what I was thinking when I did that. Thanks for pointing it out.
I got everything right in the post!
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TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
Welcome to the forum! Hope your truck turns out well!
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Verdad Gallardo No, they weren't on the engine. I looked at it briefly before taking it to machine shop for prep work, but I didn't see where there were any holes that would have had them. There were definitely not any "open" holes that I can remember. I guess I'll double check when I get it back from machine shop.
Thanks for all the help and info
Thanks for all the help and info
Thread Starter
Teching In
Joined: May 2019
Posts: 6
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I think I'll talk to my dyno guy and see what he had to say about it also, but just in case, if you can get that pic to load, I'd appreciate that!
TECH Senior Member
Joined: Jun 2016
Posts: 22,298
Likes: 3,619
From: Central Cal.
I would keep the knock sensors, as they are a good fail-safe that can pull timing under knock conditions. AND it IS totally tunable. That way you can run timing closer to the edge of knocking for best efficiency.
Originally Posted by Qwikslvr
I guess I just think the "hassle" to drill and tap the block to install the knock sensors is......... Something I don't really want to do, and don't know where they go! Lol don't want to screw up this block
Thread Starter
Teching In
Joined: May 2019
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