looking at swapping anything and everything necessary from an 03 SSEi to my 04 SE. and would like would draw on you guys'* extensive knowledge on the matters at hand.

i will have a nearly complete and working donor car (03SSEi) and a complete and working car (04se)

so what can i expect to have to swap and what difficulties might i run in to?

questions and suggestions?

I would go with the entire drivetrain and wiring/harness/pcm.

I mean entire drivetrain to the axles

I dont know enough about the new l36 cars to know if the exhaust is the same and the fuel pump etc are the same.

in theory it should not be that hard since the body styles should be the same and the wiring should not be a huge issue but that is hard to say with out FSMs

my buddy blown buick has a 1996 buick park avenue and he swapped out the origional L36 and put in a L67. i remember one problem that he did have was that the exhaust didn't line up the same, but i dont know if it would be different on your car

The fuel pump is also not the same. That must be changed. As I recall, the FPR is the same, but you'd have to have the L67 fuel rail anyway, so it'* of no consequence.

Is 2004 the first year for drive by wire?

Drive by wire was never used on the Series II. I believe the Series III'* were the only ones to use it.

ahh i was thinking 2004+ gp

This is some of my experience from my 97 L67 swap in to a 90 Bonneville and how it relates to your swap consideration.

Primarily, this swap was a bolt-in modification rather than a motor swap. I determined through dimensions listed in the FSM that the subframe would bolt to the 90 without any modifications. This meant that all of the 97 mounts could also be used so no custom mounts would need to be fabricated. Since you're considering a drive train from a 03 to go in your 04, you will also be able to simply bolt in the donor'* if desired. Some research of the part numbers of the mounts used with an L67 vs the L36 could determine if it would be necessary, convenient or a waist of time to use the donor subframe.

Along with the subframe assembly, I used the 97 steering rack. It had the MagnaSteer option which was unheard of in 1990. The steering functions as it normally would in a 90 but since there are no electrical connections between the rack and PCM, input effort does not differ depending on driving conditions. You would need to determine if your 04 already has the MagnaSteer option. If so, you should be able to use the existing factory connectors.

Once I had the 97 subframe (complete with motor & trans mounts) in the vehicle, I installed the engine/trans/PCM/harness assembly as a whole. The drive axles were really the only thing that was removed for the installation. This is the way I would recommend that you perform the removal and reinstallation if possible. The donor drivetrain was dropped out the bottom but reinstalled in the 90 from the top. This was only due to the tools we had at the time. Tow truck to lift the car off the engine and engine lift to install it. From what I see in other member'* 00+ engine compartments, it does appear that removing/installing the drive train from the bottom is the way to go. Don't take my word for it though... someone with more experience with the 00+ body style will need to give some input.

Along with the engine wire harness, I also obtained the "car" half of the engine harness connector/grommet. This allowed me to integrate the 97 wiring to the 90. Although this would probably not be required in your swap, it would certainly help to have it for reference. The FSMs aren't crystal clear as to what wires are specific to an L36 vs an L67. Having the donor'* other connector half will allow you to compare the wire colors, cavities, and physical presense at a glance and allow you to insert any missing circuits. One such circuit should be a fuel pump module. I'm not positive about the 2000+, but at least 97 and 98 L36 equipped vehicles did not have this circuit. If this is the case, you could simply extract the correct wire from the donor'* connector, insert it in the appropriate cavity in your factory connector, and run wires to the module.



This is just a sample of things that you should research before jumping in. Other things to check are fuel pump capacity and gauge senging unit ranges. Many of the specifics can be answered with the factory service manual for your year.

Well, I put a 1999 L67 in my 1996 L36 equipped car. It was really pretty easy, considering how different the motors are on the inside.

The wiring harness should be very close. On my car, there were a few differeances, mostly just between */C vs. N/A and not differeance between model years.

1) Fuel pump wiring. The */C cars have a module that throttles back the fuel pump during light load conditions. The N/A car doesn't. So, there'* the control wire and module near the fuel pump for that missing in your '04. I think the connector for the pump is defferent, too, between L36 and L67. You don't really need the module, you just need to make sure you have the fuel pump from an L67 car (of which I'm still missing, but until I mod, I'll be ok). You'll probably need to figure out the proper way to wire up the L67 fuel pump, but that shouldn't be too hard. Because you've got complete car, you'll probably be able to use the module and pump assembly from the '03 in your '04.

2) Exhaust. I'm pretty sure that the L67 has bigger exhaust than the L36. If your lucky enough, you might be able to use you complete '03 exhaust on your '04. I'm stuck with my N/A exhaust for now. You should be able to, at the very least, be able to have an exhaust shop order the down-pipe for an '03 SSEi and weld it to your '04'* exhauset (which is what I did to my car.)

3) BCS wiring. This dumps boost at the command of the PCM. It'* really 2 wires that you need to run if your using the '04 harness. No big deal, just order an L36 -> L67 wiring harness conversion kit. Best solution, though, is to see if you can use the '03 harness.

4) MAP sensor wiring. It'* really just a different connector. The aforementioned conversion kit should take care of this for you with a connector the has a male plug for the L67 MAP and a female L36 plug for the L36 wiring harness. (See if '03 harness will work, again)

5) EVAP control solenoids. The L36 has them on the front (towards the radiator) side of the UIM, while the L67 locates them behind the supercharger, near the MAP sensor. What I did was to just locate them on the front of the supercharger, and ran normal vacuum lines between them. There'* no where to mount them, but they stay put. The only thing wrong with this is that I can't put my engine cover on, but oh well. That'* not the end of the world. Again, if you can use your '03 harness, yoru golden because you can mount them where they came stock.

6) I had a problem because they changed alternators in '98, but the only thing I did was buy a '99 alternater and get a '99 plug and cut off my '96 plug and put the '99 plug on. Worked great, but you shouldn't have to worry about that.

7) Computers. In '96, the computers between N/A and */C were the same, so the only thing that I needed to do was to flash the computer with a 1996 Supercharged Bucik Park Avenue Ultra VIN in a Tech-II. Worked great, and the Pass-Key II system didn't cause any problem because I didn't change the computer.

I just looked up (on GMpartsdirect.com) the computers in an '04 SE and an '03 SSEi. They're different numbers. That could spell many headaches. I would recommend pulling both computers out and checking any differeances between the two, like the the harness connectors. Report back with your findings.

8) Transmission. You'll need to use the transmission from the '03. It'* the HD version of the 4T65-E. Don't try to use your '04'* transmission. Also, the half-shafts are different between the HD and non-HD versions of the trans, but I believe only on the passenger side??? On my car, I needed to buy a passanger side half shaft because it'* 39 splines on the differental side instead of 33 or 34, whatever a stock L36 is. The outside was the same, though, so it fit right in. Since you've got a complete '03, I would imagine that you'd be able to mix and match whatever half-shafts worked for your car.

Also, what'* wrong with the '03 SSEi. Totalled? What is unusable in it? I assume that the '04 is a perfect specimine of a car, that'* why your putting the L67 in it.

Sorry for any spelling errors, this is a lot to type. I'll be back with more thoughts, and am thinking right now, your biggest problem is going to be the fact that your '04 SE might have a different computer than you '03 SSEi. You might be able to use the '03 computer in your '04, but I really have no idea. I think FSMs for both cars would be a wise investment, considering the scale of you project. When your done, I'm sure someone would love to buy them off of you.

With FSMs, you'll be able to compare the wiring differeances between the cars. But, I'll let is churn in my brain for a while and tell you what I think. So, until then, I wish you luck in your project. Sounds fun. I love my car, because it'* an L67 Park Avenue that'* not an Ultra. Who would have guessed? It'* late, I'm tired. I'll check in tommrow.

Oh, how long do you plan to take? Do you have unlimited time to work out any issues, or do you need to car to be done in 2 weeks?

I think haveing two complete car will help you a lot.

Forgot to mention, the fuel fail connectors are different between the L36 and L67. I've got a hill billy soultion on my car right now, where I used the steel connectors from my L67 and melted the nylon fuel hose to them, then hose clamped them down. I know it'* not the best, but it works. I don't know what the proper solution would be, but it'* something to thing about.

Another thing, seat of the pants feel when the pedal is to the metal. You'll feel a much stronger push with the L67 and will need to compensate in your driving habits. Also, the whine of an M90 is addictive. You'll find yourself laying the hammer down just to hear that delightful whine. Fuel economy will suffer. Happiness will prosper. Tire squeeling is inevitable. You'll leave more rubber down on the road then you'll care to imagine. Tires will become a commodity. Cops will be all over you now. Ricers will be in your rear view mirror more now, and you'll be more suseptible to speeding tickerts. Be careful, and have fun.

You have been warned of the dangers of an L67.