Hello all, I've been lurking for some time and thought I'd finally post. While I've owned a few LS vehicles (Currently a 2014 SS sedan, previously a 2009 G8 GT), I've never had a LS4 variant. My pipe dream has been to swap one into my older Monte Carlo Z34. Now I know that LS4 swaps are nothing new, nor are manual transmission conversions to them, but the combination I'm attempting may be somewhat rare. The donor vehicle is a 2006 Impala with a junk transmission. The recipient is my '98 Monte Carlo Z34 (car in my avatar) that is a top-swapped SC3800, and that has also been converted to a manual transmission Getrag 284 five speed. The trans swap was done in 2013 and the car has been running and driving perfectly since; albeit as a summer cruiser only. My goal is to mostly keep it "stock", save for a DOD delete and some other odds and ends. I finally got around to pulling the motor out of the donor car this weekend, only to find it's not the original engine as denoted by the E67 ECM, instead of the E40 that I was expecting to see. Sure enough, the CPS is a gray connector as well. The reason I wanted the older version is so I could keep things simple and "era correct" with the DBC. Also, the Monte Carlo uses the same shape/ size PCM as the P59, which was another bonus for placement in the engine bay. I know it's not difficult to convert to DBW, but I was hoping to avoid it. Anyway, for now, here's a couple pics of my "junk" 5 speed mocked up to the engine. Everything fits great. The only thing I'll really have to fabricate is the motor mount placement on the Z34 cradle for the LS4, and the abutment for the output shaft of the transmission.

 

Sounds like a fun project. I nearly bought a 97 Z34 Monte back in the day. I currently own a 2017 SS and a 2007 Grand Prix GXP. It appears we have similar taste in cars. What is your goal for the LS4 swap? I would say you need to get the trans built by Nichols Performance Trans (there are a couple other shops that are able to rebuild these trans to last, but Justin has it nailed down). I would delete DOD as well, but you are probably familiar with that from your G8. Are you looking for more power or just something different? I only ask because you can probably get your top swapped 3800 to make similar power to a stock LS4, but I understand wanting to do the swap anyway. What was the donor car for your LS4? Are you parting the rest of it out?

 

I guess my goal has mostly been to have V8 noises where they were never originally present, if I'm to be perfectly honest. My own version of a sleeper I guess. I am absolutely deleting the DOD, mostly for the obvious, but also because of cam and intake options/ choices in the build as well. I am not familiar with any transmission shop being able to do anything with these transmissions, as according to W-body and 60degreeV6.com, these transmissions were only every serviced by Getrag directly, but maybe that's changed. I'm not too worried though, as there have been a few that have been put through their paces, most notably a guy over on W-body.com back in the day that pushed over 500hp through one as a daily driver via a turbo'd 3800. You are also correct that it's fairly easy to milk power out of the 3800, but my goal with this, as stated above, has been simply been for the V8/ LS-swap aspect. The donor is/ was a 2006 Impala, which is more or less being parted out. If you need anything from it, I'm letting it all go for cheap to free as I have little to no use for it. I simply bought it for the obvious.

 

Ahhh, so you're keeping the Getrag. I was thinking you were going to use the 4T65EHD. Have you figured out the starter provisions since the LS4 is different? There is a modified oil pan solution that is used when people switch to the 4T80E. If you want to get rid of the 4T65EHD they are worth something if working. Nichols Performance Trans is probably looking for cores to be used for builds as well. You should be able to find people interested in parts on the LS4 facebook groups. I would be interested, but mine is a Grand Prix GXP and very few parts interchange.

I presume you've looked into swapping to an LS6 intake and a different throttle body to compliment your cam swap?

 

I suppose I should have clarified that I will be retaining the 5 speed in conjunction with the addition of the LS4. Regarding the known swap complications: I have an order in with LS4 King/ Furches Performance for the Moroso oil pan with starter, so that solves that big hurdle. I know Fieroguru has the 6 speed solution, but nobody has done anything for the 284 that I'm aware. I do have the 4T65 still. It was still in driving condition when I pulled it; just slipping on shifts, though it shifted through all the gears ok. I've considered rebuilding it and selling it as I'm familiar with the standard 4T65, which as I understand, is identical save for the starter provision. If, however, the cores are valuable, I might just get rid of it that way as there aren't many LS4's running around my small rural area. I use my wife's FB as a proxy as I don't have my own, but we (she) are part of the LS4 group on FB so maybe I can chock stuff up on there. I appreciate the suggestions. On a unrelated note, do you or anyone have any cam/ exhaust suggestions for these cars? The kid in me wants it to sound like a Corvette, but every LS4 I've heard (YT vids) sounds like a half ton Chevy with the mufflers hacked off. I don't care if I have to spend money on some elaborate Borla setup or equivalent; I just want it to sound GOOD.

 

I think the exhaust sound problems you are running into has to do with the majority of owners doing cheap exhaust mods and the way the exhaust is on the car. Otherwise, its an LS V8. You should be able to do whatever you want to get it to sound proper. Do you want it to chop or just sound more like a Vette? Texas Speed would be my go to for a cam swap. I think the biggest thing for sound will be headers and running larger exhaust the entire length. Duals the entire way and dual cats will help, but I don't think there is a reasonable way to do that.

 

I have been looking cam and DOD delete stuff on both Texas Speed and Brian Tooley Racing. I'll have to choose eventually. As far as sound, I'd prefer a more 'Vette-like sound, but if nothing can achieve that, then a good choppy lope would be my second choice. I've only seen two different headers for these: one defacto set from Doug Thorley, and another by OBX or some knock off. Either are fairly expensive from what I've seen, but I suppose that's the price to pay for such a limited application.

 

Hey, I have a 2001 Earnhardt Monte that I am doing a very similar swap with just for obnoxious v8 noises for summer driving. I picked up an 06 monte thinking it was the older gen ls as well and found out later it was an 07 style.. lol

What are you doing for transmission mounts? Is the Z34 cradle aluminum as well like the other gens? My ls4 and 3800 cradles have different locations for the steering rack and figured it was mandatory to start with the ls4 one, would be great news if I didnt.

I am in between a 282 (only thing I can find with a donor car for peddle box/shifter plus lots of fiero replacement parts) or a 4t80 swap, the F40 doesn't look very attractive to me as the price has gotten insane on them over the years.

My cam/exhaust choice so far from research is going to be a comp cam thumpr cam(the sound I'm going for, idc about performance/gm asa cam is close second), ebay headers, and a cutout to a side boom tube with oval tubing. I'm also leaning towards a Volvo electric steering pump to clean up the pulley system and fit a 92mm intake on it and MAYBE running an external davies electric water pump to get rid of the rest of the accessories leaving only the ac and alternator.

 

With a 4x 58x reluctor setup you'll pretty much have to be DBC unless you decide to use 24x components. Or standalone efi

 

I'll be reusing my original engine cradle currently bolted to the car. My 5-speed setup is already a running/ driving unit, so there's not much I need to alter there. The transmission mount (x1) is just the factory mount, as the provisions are leftover from gen 1 W-bodies (that the transmission was originally equipped in). Additionally, the cradle has the plate in the right-rear corner for the engine/ transmission mount of the LS4, since the LQ1 DOHC 3.4 (used from 91-97 through both generations of Chevys) used the same elaborate transmission bracing with the 4T60. I haven't measured the bolt pattern on the mount plate, but there are two offset holes in the cradle plate just like on the LS4 cradle, so I'm fairly confident it will bolt up in that spot. That leaves just the front/ left motor mount, which I believe I merely have to drill a couple holes in the cradle for that is all. Worst case scenario is I might have to do some welding, but since it's a steel cradle, it's much more doable for me as opposed to the aluminum one (I don't have an aluminum welder).

In regards to the steering rack, I read somewhere that the mounting is the same (two bolts of course), but if it's not, I'll just reuse the MC rack, and bolt the LS4 lines up to it, since they're in virtually the same location on the rack.

If you do go the route of the manual, the 284 is the best candidate for the W-body (your Monte Carlo) as despite it's paltry rating, its been proven to handle nearly triple of its rated power level capacity. If you decide on the 282, it'll work, but may not survive the power of the LS4. The pedal boxes are the same between the 282 and 284 cars, though you can get by with just adding a clutch pedal to your current pedal box by making a mount for it.

I unfortunately have no inputs to the cam and exhaust choices as this will be my first foray into modding LS motors to this degree. Good luck with whatever you choose, and if it's MT related, feel free to ask any questions and I'll try to help as best I can.

 

A small update. I finally got it up on a stand after checking compression. All cylinders were around 175psi, so no worries there. I wanted to keep the return fuel system on my Z34, so I found a 97-98 Vette rail on Car-Part and bought that last month, and then a couple weeks ago found a LS6 intake and TB from a Camaro on my local Marketplace, so I got that situated. Below is a pic of it just sitting half-@ssed on the motor. I talked to my local machinist and he can cut and re-weld the OPSU on the truck/ non-DOD valley cover for me for cheap, so I'll go that route to keep it simple, as I was looking at the Katech setup, but wow they are some money.

 

Dang, I've forgotten to check back and update, but I've made some progress in the last year (nearly a year since I've last posted, what the heck???). Anyway, for anyone that may care, the engine is "refreshed" with new gaskets, new "stage 2" BTR cam, dual springs, pushrods, DOD delete including plugged oil towers and non-DOD valley cover. Also are new timing set, GM oil pump, oil filter bypass valve, custom oil pan, starter, flywheel, clutch and pressure plate assembly, and some other items I can't remember off the top of my head.

 

Looks like it is coming along nicely. I always admire people that do these involved projects.

 

Nice and interesting build, good luck, look forward to hearing more.

 

Thanks for the nice comments. Yeah, the whole FWD/ LS4 thing isn't very popular, for obvious reasons, but they're the car(s) I grew up with, so here I am, Regarding the swap, I will be using most of the LS4-related engine parts, including hoses, AC lines, and radiator and fans. I think I can reuse my Z34 AC condensor as it literally just wedges in the front core support with rubber blocks from factory. That way, I'll only need to make one line modification going between the condensor and AC compressor. The Z34 runs an accumulator/ drier assembly with orifice tube, as opposed to the LS4 TX valve setup, so the line arrangement is slightly different.

Beyond that, the main things I have left to complete off the top of my head:

- Finish welding the strut tower area I had to cut for clearance of the alternator pulley
- fabricobble my engine mount brackets
- route wiring and connect to PCM as well as integrate with Z34 chassis wiring
- obtain a LS7 MAF (preferably) though I can use the LS4 to start I suppose
- connect exhaust
- install a bigger fuel pump; likely a Walbro unit

There's likely some more odds and ends, but I am confident of starting it up and driving it around this summer.

 

Carkhz, can you tell me if it was challenging to get the Getrag 284 working with the SC3800? I have a SC3800 and was thinking of going the 284 route. Not sure as to how complicated it would be and what would be needed to get this going? Any info. would be greatly appreciated. Thanks!

 

Getting the 284 to work with the 3800 wasn't really too bad. It's all the other items with converting the car to a manual that was the challenge. The only 3800 to manual transmission specifics that you'll have to contend with is getting a flywheel and clutch kit for it, which is not terribly difficult. For the flywheel, you can either purhase a premade one ($$$) or go the budget route which is to buy one for a 3800 F-body (90's Camaro and Firebird) and have it machined down to a thickness of .840". I literally did it on a brake lathe and it worked just fine. However, I recommend getting an OEM or used (hopefully OEM) flywheel as I went through two new aftermarket ones that had casting voids when I started cutting them (cheaper casting?). For the clutch kit, any kit for the 91-94 GP, Lumina, Cutlass cars with the 3.4 DOHC/ 284 will suffice, though you'll likely need to go to a higher performance version (SPEC or California Custom Clutch) to handle the power levels.

The other aspect is the tuning and wiring, which if you have access to HP tuners, you can take care of. Since there is no manual transmission tune file for a 3800 W-body, I had to do a couple things: jumper the transmission range switch wiring to [D] range (or you could leave it connected I suppose and just manually toggle it), and then disable the automatic transmission related fault codes in the tune file. After that, the car drove perfectly fine, including cruise control working.

That's about it off the top of my head for the main items. Feel free to ask anything else about it.

 

Thanks for the reply Carkhz. So... I currently have a 5 Spd Getrag 282 transmission. Am concerned about it not being able to handle the load of SC3800 with Cam upgrade, 3.2 pulley and other goodies. I understand a lot of people have had good success with the 282 as long as its not abused (and some have mated it to V8's).

I purchased a few items for this Getrag 282 last year. However, I'm in the process of getting a 5 Spd Getrag 284 from a 93 Chevy Lumina --- Just concerned about the torque issue with the 282.

Would these parts that I purchased for the Getrag 282 work with the Getrag 284?? Or have to get all different parts?

1x SPEC Flywheel for Getrag 282
1x SPEC STAGE 3+ Clutch for Getrag 282
1 x Getrag V-6 5 Speed Transmission Replacement Cables
1 x Getrag V-6 5 Speed Transmission Replacement Cables
1 x V-6 5 Speed Getrag Aluminum Slave Cylinders
1 x Cast Aluminum Clutch Master Cylinders

OR would I need all different / new parts??

Also, I think the Spec Flywheel might work with the 284?? But the Spec Stage 3+ Clutch will need to be changed --- Not sure??

Some info. I found out...

- 284 requires different axels than 282
- 284 will not bolt up to the same mounts
- 284 has a throw out mechanism for a pull-to-release clutch which would require work to adapt a conventional clutch
- 282 pushes the TOB to activate clutch
- Some say... 284 clutch wont work with the 282 clutch
- would need Hydraulics for the 284

Overall, I'm trying to understand what I need to get and or modify to get this working with the SC3800??

 

Hi Carkhz,

Can you tell me if a Getrag 282 linkage work on Getrag 284??

Thanks!

 

Sorry for the late response. I don't check back in very often as I've not been tending to my project car for awhile. Between life (family) and my SS being the main summer/ fun car, and an abundance of fixing everyone and their grandmas (it seems) daily drivers, I've since been dragging feet on the Monte.

Anyway, to be perfectly honest, I'm not certain of all the differences between the 282 and 284 besides the transmissions themselves.

The flywheels appear to be different between the 282/ 284 cars, but I cannot confirm. I'm just glossing over part numbers and they are different. However, it may be moot if you're adapting them to a 3800.

The shift/ select cables may be interchangeable. I know they're the same connection at the shifter end as I initially wound up with a 282 GP shifter in my Monte before sourcing one from a Lumina Z34. The transmission end may be differnent, but it might not matter: My select cable bound up on a test drive and snapped off. I ended up finding an open-end ball joint (aka: Heim joint) that was a perfect fit for the cable end.

The slave cylinders are completely different, as the 282 uses a standard push-type clutch, whereas the 284 uses a pull-type. As such, the clutch kits are different; specifically the pressure plates. The clutch discs themselves may or may not be the same, but again, I've not been able to compare outside of checking part numbers. The clutch master cylinders should be the same though.

The axles may or may not be interchangeable. Most of the interchangeabiltiy issue is with guys swapping from auto to manual (like I did). There are some tricks like swapping inner and outer CV joints, but I believe the best option is to source from the donor vehicle.

I can't think of much else at the moment, however if you check out W-body.com and the Grand Prix forums, there are a bunch of discussions that go into more detail. Good luck!