So last fall I blew the bottom end out of my 01 pace car, no big deal so I bought a used L36 block off of ebay that claimed to have 60k miles -- so it came in and looked great. I don't have a garage currently so I paid a trusted local shop to install it, they told me it looked great and they got it all together well it knocks.. like terribly. So I can't afford to buy another block and pay for it to be installed at this point but an opportunity came up today.


My long term girlfriend's uncle died last year and her aunt now wants to sell his 06 grand prix. The car has 100k miles but the body is junk. So, my girlfriend wants to buy the car off her aunt for 1k and give it to me so I can swap the engine/trans (my father says my transmission is getting tired).


So I guess I am just trying to figure out if this is the best route to go, I can't afford to buy a new reman block which is what I would prefer to do, this car is like my child I have no plans to ever sell it as long as I'm alive.

 

The engine block, heads, lower intake would work just fine to swap. You would have to reuse your throttle body and upper intake though. Unless you do the "l26 plenum swap" then you would need a throttle body adapter to bolt your throttle body to the l26 uim.

The trans I'm 99% sure can not be interchanged

 

I just had a conversation about the same transmission with triple edge performance, and they confirmed the transmission DOES NOT interchange... electronically or physically (as a 1 for 1 swap)

 

Thanks for the replies guys,

So even if I have everything from the grand prix the transmission wouldn't work in the monte?

As in the PCM wiring harness and all?

I thought it would just be as easy as dropping the tranny/engine out of the grand prix and swapping it into the monte..

 

As per my conversation with triple edge, I remember 100% that electrically the transmission was different, so swapping the electronics would solve that, however it doesn't solve the physical differences and as IIRC, there were differences. Triple Edge basically told me there was an older "HD" trans that physically fits (but is electrically wrong), but the newer ones like your pontiac has, wouldn't... that said swaping the electronics and harness would work to solve the electronic side of things and ANYTHING can be made to fit with enough fabrication and welding...
---(side note, triple edge also said they could get the correct fitting transmission as a core, rebuild it, and have all the internal transmission wiring set up so it'd be a "plug and play" transmission swap)---

however you're talking a lot of work for an as you previously stated "tired" condition transmission. You'd be better off getting the stock transmission rebuilt and keeping with the oem monte carlo computer system and use the good long block from the Pontiac and perform the UIM swap from the Pontiac as previously mentioned... remember the Pontiac was a 4dr, not a 2 dr, and you're asking for a lot more complications than just simply eliminating two doors. keep it simple, and you'll simply enjoy it sooner and more when it's done. Now if the Pontiac was supercharged, that'd change things a bit, however even then... I'd still keep things as much monte carlo oem as possible to keep the swap simple and less chance of burn-out on it, and easier diagnostics and repair when something in the swap "doesn't go right"...

 

little bit of extra info, the throttle body adapter for the UIM would be the exact same one for a series 5 (GTP) supercharger if you decided to go the boost route later on with it... vendor named, "QualitySuperchargers", on ebay sells the adapter plate for cheaper than anyone else btw...

 

here's a copy of the email from Triple Edge Performance's "Dave"... now mind you, this was in inquiry where I was asking about swapping over a 05 GTP transmission into my 01 MC SS, so there is a little more additional info than you might need/want, but all good stuff:



Interchange wise- 2002 and earlier are electrically identically, and 2003+ are different. To retain the 2001 PCM (computer) in your vehicle you will need to use a transmission in this year range. In regards to our rebuilds- there is no advantage early or late as we address the problem areas and everything is updated as needed so both model year rebuilds will feature the same parts. Electrically it will be much easier to stick with the 2001 parts. We can build a core we have here that will correctly match your Monte Carlo. The internal transmission on the Monte Carlo is different that the same year Grand Prix, so even if you sent us one we would still need to converter a few things to correctly work in your vehicle. Our core fee for an early HD transmission is $300, so money wise it would be cheaper to source it from us than to by a used one then pay for shipping to get it here.

Engine wise- the 2004+ Grand Prix uses a Drive By Wire electronic throttle body system and there is no cable that goes down to the gas pedal. You will have to use an adapter plate and different throttle body to work with that style (Gen V) supercharger. It is a popular upgrade so parts do exist, but if you are looking to buy a complete used engine and drop it in and go then this is not the easy route to take without some headache. Otherwise physically it is a direct drop in replacement for what you have and all accessories (except the passenger dogbone mount) will bolt right up on this engine. The 2004 Impala SS and Monte Carlo SS came with the supercharged engine option and was a carryover that still had the Gen III supercharger and a conventional throttle body and cable setup that will work with your vehicle without modification.

The PCM will need to be custom programmed to properly function with the new transmission and engine. There are a few ways to do this correctly and a LOT of ways to do it wrong. Most of the 3800 vendors do not offer a 100% correct tune that is sold to be correct- but I will verify is not and have been down this road with customers in the past. An on-car tune is the best course of action but I know that is not always an option depending on your area and if you know a reputable tuner that is very familiar with 3800 powered vehicles and more specifically doing engine swaps. For this I recommend a good local friend of mine that specializes with mail order custom tunes. His company name is Sinister Performance and website is GMTuners.com. His name is Ryan and does great work with custom tunes for swaps. Sometimes it can take a few times to get things correct but he will do it until it is correct for the vehicle and setup.


I hope this helps out, let me know if you have any other questions.



David Norris

 

SSBlue,

Thank you so much, you've been a very big help.

I assumed it would be a simple swap but clearly it isn't which is fine, I think you've put my mind at ease.

I want this car to last forever so I think I'm just going to save up and next tax return season buy a reman such as this:Reman engine

I think this will be my best route, I only put maybe 5k miles on it per year now so I should be able to make it another season and then swap out the trans or rebuild it.

Thank you!

 

Great information David!

 

Well, I think getting the Pontiac for parts is still a smart move though, as you know that it's a good motor, and you know the maintenance history on it, and that'll solve your "knocking" motor, so you can enjoy your Monte Carlo. Also rims/tires and as previously mentioned upper intake, and IIRC the rear swaybar is an upgrade for most Monte Carlos. And when you've taken off and parted out/eBay whatever you can, the stripped hull is still worth $200-$300. It's not really worth it to buy a new motor... But a built transmission, that's well worth it...I'd spend your tax money buying the best, quality built transmission you can