Chevy 350 conversion

Frobisher

Well-known member
Dec 27, 2012
107
39
Pennsylvania
Till one morning you find that it takes a little longer to shift out of the 1st.
Then you think you'll just change the fluid a couple of times and it'll go away like it did the last time.
And it doesn't.
Then it takes a fully city block to shift out of the 1st.
Then it takes a mile to shift out of the 1st, but it happens in the desert, so you don't care.
Then you pull the Y-pipe and transmission pan and change the filter, too.
It still does it.
Then you realize that you need to replace some obscure parts in the transmission oil pump, and need to pull off the exhaust, driveshafts, and transfer case.
You find that the parts are few and far between, and shops willing to work on these transmissions are nearly inexistent.
You still find the obscure parts and do the job yourself or farm it out to an indy shop you trust.
Pay your bill, take the keys, and drive the truck trying to convince yourself that it is fixed. It isn't.

This kind of robust.
And then it won‘t shift into 4th/overdrive after all that, so it’s either drive it like that or toss a flare in the back and walk away. I’m currently at the drive it like that stage…
 

LandyBobandy

Active member
Jul 8, 2021
34
8
Colorado
Nick Markiw, my best authority on LS swaps, suggested $10k ballpark figure for engine+transmission swap, assuming most of the work is done by owner.
The donor drivetrain is barely a half of that amount.
10k seems steep. The conversion kit linked above is $2500, and you can get a 5.3 in good shape for half that.

Where'd the other 5k come from?
 

robertf

Well-known member
Jan 22, 2006
4,408
145
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10k seems steep. The conversion kit linked above is $2500, and you can get a 5.3 in good shape for half that.

Where'd the other 5k come from?

transmission
shifter
exhaust
ecu and harness that are new enough for a 5.3 with a 6 speed
tuning
fuel pump

thats at least $3000
 

robertf

Well-known member
Jan 22, 2006
4,408
145
-
I'd stick with the standard ZF to save time and money , if it's healthy.

I ran some comparisons on automobile-catalog to see how badly the ZF would be stressed. I'm shocked to see how similar the torque curve is to the early gen 4(?) gm v8s. I don't think I'd consider bothering with this swap.


Now a proper 350 might grenade a ZF in no time, but these days those are looking as archaic as flathead fords and nova inline 6's. Plus they have some coolant leak self destruct problems kind of like the rover v8
 

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LandyBobandy

Active member
Jul 8, 2021
34
8
Colorado
I ran some comparisons on automobile-catalog to see how badly the ZF would be stressed. I'm shocked to see how similar the torque curve is to the early gen 4(?) gm v8s. I don't think I'd consider bothering with this swap.


Now a proper 350 might grenade a ZF in no time, but these days those are looking as archaic as flathead fords and nova inline 6's. Plus they have some coolant leak self destruct problems kind of like the rover v8
I'm a mile high, so the current 4L can just barely keep up with the lift and larger tires. The extra power and efficiency may be just enough to justify, even if it's putting extra strain on the ZF. Is it even worth trying, especially if I only plan to use it as a stopgap for a year before swapping in a newer gearbox? Or should I just budget for a whole drivetrain swap?

Also, has cryo-treating the gearbox internals proven effective?
 

robertf

Well-known member
Jan 22, 2006
4,408
145
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I think its the clutches that fail, but I've never had a complete ZF failure and thats 280k with never a filter change and an undrilled lt230 gear. The last 40k of that was sketchy, especially when taking off from a stop while pointing up hill. The console was also hot enough to regularly shutdown an iphone.

I sympathize with the 4.0 at elevation. I put a 4.6 in after my first trip to CO.
 
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Cap065

Member
Aug 14, 2021
7
5
NC
I have a 2002 Disco 2 with a 5.3 LS and one of the early Alternative Conversion D2 kits. It has a ZF 4HP24 from a 2003 Disco. The LS is an aluminum block LM4 from an Envoy XL. Significantly more power than the old 4.0, and a bit more than the other Disco I had with the 4.6. It’s probably around $5k for all the parts once you are done.
 
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robertf

Well-known member
Jan 22, 2006
4,408
145
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When I read that guy's development thread it mentioned keeping the factory ecu. does your conversion do this? I've done enough junkyard TBI swaps back in the day to have a difficult timebelieving a rover 4.0 fuel and ignition strategy would work well on a different engine. Does the check engine light randomly go off or any other anomalies?
 

Cap065

Member
Aug 14, 2021
7
5
NC
When I read that guy's development thread it mentioned keeping the factory ecu. does your conversion do this? I've done enough junkyard TBI swaps back in the day to have a difficult timebelieving a rover 4.0 fuel and ignition strategy would work well on a different engine. Does the check engine light randomly go off or any other anomalies?
No, it uses the GM ECM to run the engine. There is an interface box that goes between the GM stuff and the Land Rover ECU. Check engine light is connected to GM ECM and only comes on if there are problems from that. Rest of the dash works normally. GM ECM is very easy to tune and change configurations with aftermarket software. That’s probably one of the best parts of switching to the LS.
 
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robertf

Well-known member
Jan 22, 2006
4,408
145
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No, it uses the GM ECM to run the engine. There is an interface box that goes between the GM stuff and the Land Rover ECU. Check engine light is connected to GM ECM and only comes on if there are problems from that. Rest of the dash works normally. GM ECM is very easy to tune and change configurations with aftermarket software. That’s probably one of the best parts of switching to the LS.

so does the ZF 24 end up in the factory (for a 03/04) position? Any underhood pictures?
 

Cap065

Member
Aug 14, 2021
7
5
NC
so does the ZF 24 end up in the factory (for a 03/04) position? Any underhood pictures?
ZF 4HP stays in the factory position. Engine sits back far enough to still use the Land Rover viscous fan. Reuses a lot of factory stuff, like Land Rover fuel pump. Not the best pic, cleaned and changed things up a bit after this:5C0F37DE-35AA-4495-B2E3-75B97A97D8F1.jpeg
 
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Knightspirit

Well-known member
Sep 22, 2019
204
60
Mount Shasta, CA
I have a 2002 Disco 2 with a 5.3 LS and one of the early Alternative Conversion D2 kits. It has a ZF 4HP24 from a 2003 Disco. The LS is an aluminum block LM4 from an Envoy XL. Significantly more power than the old 4.0, and a bit more than the other Disco I had with the 4.6. It’s probably around $5k for all the parts once you are done.
So just to clarify - with a rebuilt 4.6 from Atlantic British running upwards of $7K - this is a comparable swap for the price once all is said and done?
 

Cap065

Member
Aug 14, 2021
7
5
NC
So just to clarify - with a rebuilt 4.6 from Atlantic British running upwards of $7K - this is a comparable swap for the price once all is said and done?

I wouldn’t go back to the Rover V8 after this. LS is smoother, gets better gas mileage, and has more power. My Disco is heavy with roof racks, bumpers, etc. Hauls it around much better.

I got the LM4 engine for ~$750 with less than 125k on it. I refreshed it with some seals for common leaky areas, new water pump, thermostat. I had one bad coil pack that I replaced. Other than that it hasn’t skipped a beat. I had to swap the oil pan because the LM4 originally has a front sump pan and I swapped the fuel rail for a returnless aftermarket setup.

Depending on what kind of local deals you can get, and other stuff you can get with it, prices will vary. Probably from about $3.5-4k on the low end (if you can snatch up a cheap local deal and do the harness yourself) to $7.5k+ (fully rebuilt LS). $5k is a good middle ground estimate though. I have the link to the parts list around here if y'all would like to see it.
 

Knightspirit

Well-known member
Sep 22, 2019
204
60
Mount Shasta, CA
I wouldn’t go back to the Rover V8 after this. LS is smoother, gets better gas mileage, and has more power. My Disco is heavy with roof racks, bumpers, etc. Hauls it around much better.

I got the LM4 engine for ~$750 with less than 125k on it. I refreshed it with some seals for common leaky areas, new water pump, thermostat. I had one bad coil pack that I replaced. Other than that it hasn’t skipped a beat. I had to swap the oil pan because the LM4 originally has a front sump pan and I swapped the fuel rail for a returnless aftermarket setup.

Depending on what kind of local deals you can get, and other stuff you can get with it, prices will vary. Probably from about $3.5-4k on the low end (if you can snatch up a cheap local deal and do the harness yourself) to $7.5k+ (fully rebuilt LS). $5k is a good middle ground estimate though. I have the link to the parts list around here if y'all would like to see it.
Oh yes - we definitely want to see that parts list!
 

Cap065

Member
Aug 14, 2021
7
5
NC
Oh yes - we definitely want to see that parts list!

This is the one that is on the website. Very similar to what I have in my Disco.

 
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Swedjen2

Well-known member
Sep 12, 2018
556
113
California
If you are in California, you can't get this swap approved for emissions, so no license to drive on public roads.
When I move outta' here.........


Unless you are a Sovereign Citizen, then you can argue with the cops that you're a citizen of the world, not any country and your vehicle is a ship and your being kidnapped by pirates. In which case, you'll end up in the Cooler or keep paying fines. Usually both.
 

Knightspirit

Well-known member
Sep 22, 2019
204
60
Mount Shasta, CA
If you are in California, you can't get this swap approved for emissions, so no license to drive on public roads.
When I move outta' here.........


Unless you are a Sovereign Citizen, then you can argue with the cops that you're a citizen of the world, not any country and your vehicle is a ship and your being kidnapped by pirates. In which case, you'll end up in the Cooler or keep paying fines. Usually both.
Yeah - the exemption in CA is for vehicles 50 years old!! I know in OR it's 20 years - all my stuff is registered in OR for that reason....
 
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