LS4 from 2006 Impala SS 92 Lumina Z34...will it fit???

[Dustin]

Friend of mine has an 06 Impala SS with the 5.3L ls4 in it.  He got T-boned and they totaled the car.  The 3.4L in my 92 Z34 has all but given up the ghost at 170xxx miles.  I know I'm crazy, but how crazy would I be to try and shoe horn that engine into the Z34.  I know ODB1 to OBDII and all that jazz...but would it fit and could it be done with only minor modifications. 

[pwmin]

https://www.w-body.com/topic/57578-ls4-swap-begins/

[Schurkey]

Better get the '06 transmission, too.

One wonders if you could swap the entire subframe--engine, trans, suspension, front brakes, steering, plus enough of the wire harness and the computer to make it all work.

Edited October 29, 2022 by Schurkey

[55trucker]

The 4T65e behind the LS4 was never considered to be a reliable trans. There were multiple issues that have been noted since the powertrains inception.

Do some research on the reliability problems that were found.

 

[Dustin]

I am thinking of buying the whole car from him.  Insurance totaled it and he decided to buy it back from them.  He knew I had toyed with the idea of going V8 in the Lumina ever since we saw a 4.9 Northstar in one. 

[carkhz316]

On 10/28/2022 at 7:23 PM, Schurkey said:

Better get the '06 transmission, too.

One wonders if you could swap the entire subframe--engine, trans, suspension, front brakes, steering, plus enough of the wire harness and the computer to make it all work.

Yes. If one is keeping the Auto, its probably *better* to use the matching aluminum engine cradle. The only issue is attaching it to the car. The rear mounts line up with a 1/ 1.5 gen, but the front do not, and have to be jury-rigged to attached to the car. Its doable, but involves drilling a new hole in the front lower "frame" rail of the car and using spacers, and a nut/ bolt combo to attach the cradle. Theres a couple guys on the LS4 Facebook page that have done it.

I was willing to do this to get the upgraded suspension, but with keeping the 284, there were too many sacrifices to make it worth it to me.

[Dustin]

@carkhz316

The plan is to keep the engine/transmission complete.  And yes was really hoping to put in the whole subframe to get the suspension.  I have another close friend that is a fabricator, builds custom aluminum utility boxes on customer provided 1.5 and 2 ton chassis.  I wonder if he could build a mount to attach the front lower rail.  This all sounds doable.

 

[mechanic58]

I would recommend using the Lumina’s subframe. It will be easier to modify than fitting the Impala’s subframe will be. WAY easier. 

[TX_LaCrosse]

Anything can fit with time, money & fabrication.

[mechanic58]

I just swapped an L67/4T65E-HD into a 93 Z34. The donor car was a 2000 GTP, I had the entire car. I also considered swapping the cradles but it was going to be far more complicated than just making some minor modifications to the Z34’s cradle. It was a no brainer. Don’t waste your time.

[Bake82]

10 hours ago, mechanic58 said:

I just swapped an L67/4T65E-HD into a 93 Z34. The donor car was a 2000 GTP, I had the entire car. I also considered swapping the cradles but it was going to be far more complicated than just making some minor modifications to the Z34’s cradle. It was a no brainer. Don’t waste your time.

BIG Difference between L67 and LS4.  the L67 uses the same mounts as the gen 1 w-body(I'm not even sure what you had to modify as there shouldn't have been anything given you had a 4spd auto before)  whereas the LS4 uses completely different mounting than the L67 and will require custom mounts and location to use the 1st gen subframe.  

 

OP.   It's not actually that crazy to get the aluminum subframe into the 1st gen.  It's been done a handful of times and is documented on this forum what needs to be done.    you will need to drill a new hole in the front mounting spots of the subframe as well as you will most likely need to modify the passenger side strut tower for the alternator to fit.  

[mechanic58]

11 minutes ago, Bake82 said:

BIG Difference between L67 and LS4.  the L67 uses the same mounts as the gen 1 w-body(I'm not even sure what you had to modify as there shouldn't have been anything given you had a 4spd auto before)  whereas the LS4 uses completely different mounting than the L67 and will require custom mounts and location to use the 1st gen subframe.  

 

OP.   It's not actually that crazy to get the aluminum subframe into the 1st gen.  It's been done a handful of times and is documented on this forum what needs to be done.    you will need to drill a new hole in the front mounting spots of the subframe as well as you will most likely need to modify the passenger side strut tower for the alternator to fit.  

I’m aware, I have also owned an LS4 car. Its easy for people who have never done this kinda thing to talk about doing it…its not as easy as you think. Swapping that late model aluminum cradle into the 1st gen Lumina will be a galactic pain in the ass, but nevermind my opinion, I’ve only been doing this kinda stuff for 35 years. 

[Bake82]

1 minute ago, mechanic58 said:

I’m aware, I have also owned an LS4 car. Its easy for people who have never done this kinda thing to talk about doing it…its not as easy as you think. Swapping that late model aluminum cradle into the 1st gen Lumina will be a galactic pain in the ass, but nevermind my opinion, I’ve only been doing this kinda stuff for 35 years. 

 

Well aware of engine swapping a 1st gen w-body, been there done that!  There is no comparison on L67 vs LS4 swap and nothing you do for an L67 is the same as an LS4.  Don't know why you'd compare those two.  

 

OP:   Here is a thread with details and pictures of the aluminum cradle swap(about half way through the thread I think).  He used a 3800 but subframe will mount the same into the chassis.    He obviously did a lot of additional work that you don't need to do to the suspension, but gives you an idea of what's needed to swap the cradle.  IMO it's easier to swap cradles than hope you get the mounting proper height and engine squared since you can't use any of the original mounting provisions in the gen 1 subframe.    But OP you'll need to figure out what works best for you, maybe fabbing mounts is 0 concern for you.  Just remember you'll need to do mounts for both the engine and trans as the trans is shifted over .5-1 inch to the drivers side vs the original engine.