Lq4/lq9 engine question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bpmack16 · 10-16-2016, 09:24 AM

Somewhere I read you must use a 2003 and up ls engine because of some differences with mounting points with the bell housing or somethkng. I can't seam to find the article soon ask you this. Is there a year range I should stay away for when it comes to an lq4 or lq9 swap? Thanks guys.

Big Port Jimmy 6 · 10-16-2016, 09:53 AM

99-00 6.0 have an extended crankshaft so mixing and matching trans is problematic, But if you use all of the factory stuff its good to go. And they have less desirable cylinder heads.

BR3W CITY · 10-16-2016, 11:21 AM

They all will bolt up. GM only uses 1 bolt pattern on ALL LS motors with the exception of the LS4, which is tranversly mounted.

The 99-2000 have the built in crank spacer, which is fine if your using a 4l80e.
The 99-2000 also have iron heads, which work, but are the least "performance oriented" heads that exist for the engines.
There are also some wiring harness differences on the 99-01 engines if you source them from an HD/fleet truck vs a regular donor.

tlmoore2501 · 10-17-2016, 12:48 PM

Brew can you explain some of the differences in harness?I may have an odd ball so I would like to know how to identify what I have.Thank

BR3W CITY · 10-17-2016, 03:05 PM

The engines out of medium duty trucks had different emissions control stuff and longer wiring runs. Some also have a ton of extra body-side wiring that the regular trucks wouldn't have.

10-16-2016, 09:24 AM	#1
bpmack16 Registered User Join Date: Sep 2013 Location: Andover Posts: 157	Lq4/lq9 engine question Somewhere I read you must use a 2003 and up ls engine because of some differences with mounting points with the bell housing or somethkng. I can't seam to find the article soon ask you this. Is there a year range I should stay away for when it comes to an lq4 or lq9 swap? Thanks guys.

10-16-2016, 09:53 AM	#2
Big Port Jimmy 6 Addicted to Rust Join Date: Dec 2009 Location: Abbeville SC Posts: 1,030	Re: Lq4/lq9 engine question 99-00 6.0 have an extended crankshaft so mixing and matching trans is problematic, But if you use all of the factory stuff its good to go. And they have less desirable cylinder heads. __________________ Current trucks: (48 GMC100 320 inliner) Gone (48 Suburban in pieces) Sold 87 GMC CCSB 5.3 4l60E Daily Driver ECTA National record holder XO/PP We never really grow up, we just learn how to act in public.

10-16-2016, 11:21 AM	#3
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: Lq4/lq9 engine question They all will bolt up. GM only uses 1 bolt pattern on ALL LS motors with the exception of the LS4, which is tranversly mounted. The 99-2000 have the built in crank spacer, which is fine if your using a 4l80e. The 99-2000 also have iron heads, which work, but are the least "performance oriented" heads that exist for the engines. There are also some wiring harness differences on the 99-01 engines if you source them from an HD/fleet truck vs a regular donor. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

10-17-2016, 12:48 PM	#4
tlmoore2501 Registered User Join Date: Sep 2008 Location: Paragould,AR Posts: 76	Re: Lq4/lq9 engine question Brew can you explain some of the differences in harness?I may have an odd ball so I would like to know how to identify what I have.Thank

10-17-2016, 03:05 PM	#5
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: Lq4/lq9 engine question The engines out of medium duty trucks had different emissions control stuff and longer wiring runs. Some also have a ton of extra body-side wiring that the regular trucks wouldn't have. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

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