This winter i will be undergoing a trans swap from an 07 g6 gt with the f40 6 speed manual into my 2006 monte carlo ltz

I have accumulated a transmission from my g6 with the clutch pedal assembly and master cylinder, the intermediate shaft from the car a flywheel i had resurfaced i kept the wire harness from the car I saved the shifter and the cables and will get underway once the snow flies

 

Interesting project! I know a few Grand Prixs that have been manual swapped (one is up the street from me). This would be good to see it take shape!

 

Ill certainly be following this with interest.

One question, why do it to the LTZ? Just because thats what you have? I get that, same reason I put a turbo on a 3400 lol. Thats not saying it worked well or even made reliable power but its what I had so thats what I used.

 

I have done it i have a lot of people to get caught up with how it went

 

I did it to my ltz becasue its what i had laying around yes but i also just wanted to have something unique i really like the 3900 in my monte now i had the oppertunity to replace it and put an ls4 into it but just sold that parts car off because there is not a lot of room inside of that engine bay for a v8

 

I was literally thinking about putting a trmec t56 in my 2006 Monte Carlo SS 5.3L. Any tips would ve great, if there are naysayers, don't try to talk me out of it.

 

A couple things from the start:

1- this is pretty apples and oranges to the thread youve replied to. Adapting in a FWD manual to a FWD car is light years different from a RWD conversion on top of it all, since the t56 is RWD only. The vast majority of your work is going to be the RWD conversion itself, not the auto to manual swap portion.

2- you're best off scrapping your engine and at least getting a RWD 5.3. Your current 5.3 is the only LS with the FWD bell housing pattern so a t56 wont bolt to it as is. It absolutely can be adapted to connect, but you're going to spend more money adapting it than just buying a RWD 5.3 that bolts up with no adapters. Ideally, Id try to get a fully dressed engine - that way you're not hunting for all of the RWD specific bits - accessories, intake manifold, etc.


As for the RWD conversion itself, there's way too many variables / too little info at this point to give you any useful tips. You need to start at square 1 by figuring out what you're going to do to make it RWD:

-Convert to a full frame chassis

-Do a complete unibody swap with a RWD car (and if so, which one - there are search websites that can show you vehicles with comparable wheel bases)

-Do a partial swap of sections of a RWD car under body / subframes

-Complete custom one off fab from scratch


TBH, you're going to get this anywhere you go (not just MC forums either, this thread is common on many FWD forums). The problem is out of 1000 people that say they're going to do a RWD swap, MAYBE 1 actually does it and ends up with a running, driving car in the end.

The vast majority of people dont have the fabrication / engineering skills to do it and can't afford the price tag to drop it off at a shop to do it turn key. So folks responding tend to be ultra pessimistic when they hear yet another thread about someone pondering a swap like that as more often than not it's just pipe dreams. Ive seen threads go on for months and months planning this incredible swap out down to the tiniest detail, only for the OP to vanish or just sell it and buy a Camaro / Mustang / whatever.


To be fair, there is some validity to people pushing back / warning about it. If 1 out of 1000 successfully does it, there's a handful of other people that actually started into the process but the car ended up in the scrap yard. Either they ran out of skill, money, or even just interest - the failure rate here is super high.

 

Im 53, retired nilitary, make 9200 a month in Oklahoma and nothing but time. Fabrication, got that. According to GM the LS4 bell housing will bolt onto a T56 you'll need to take a little out of an external cooling fin on the block to get the holes lined up. I am keeping it fwd, its either a T56 or one out of a G6.

 

No offense, but someone has been giving you some seriously misleading info.

So the LS4 has the GM metric bellhousing pattern which is mostly a FWD pattern, although some older RWD uses do exist. That bolt pattern is not shared with any other LS/LT engine that came with a T56 from the factory:


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​​​Id ask your GM source to identify the exact vehicle that came with a GM metric bellhousing pattern AND a T56. Alternatively, you can research those engines above with your current bellhousing pattern and see that none were ever mated to a T56 or use the Chevy V8 bolt pattern.

I suspect your GM source meant T5, not T56. The T5 did have a bellhousing option for this pattern - such as used behind the 3800 in the 4th gen Camaro. But it's a totally different transmission and frankly isnt a great match for an LS.

Further, a few places make an adapter between the two bolt patterns (I own one made in Australia to attach the 3800 to a T56) - so if they bolted up somehow, why would places have to make an adapter?

I hate to say it, but you're never keeping this FWD with a T56 regardless how good at fabrication you are. The T56 bell housing to tail is nearly 3 feet long. Keep in mind, that's transmission only - you still need a driveshaft and a rear end (unless you get a corvette style transaxle with the differential bolted right to the transmission, but that's got to be north of 40" total length).

If you leave the engine tranaverse, you're literally going to have to make the car into a 3 wheeler and do a driver's side wheel delete and even then it'll probably still be hanging a foot outside of the driver's fender. You'll have to climb out the window to change gears.

Even if you rotated the engine front to back like how a T56 would normally sit, you'd end up with a monstrosity like those pro-FWD cars to make it actually drive the front wheels (only with the engine hanging even further out there as a t56 is way longer than the 2-3 speed transmissions they usually run, plus youve got another whole bank of cylinders beyond what the car below has):





I own a T56 car, my daily driver GTO - I can tell you that thing is huge / there's no way youre cramming that under the front end of a stock body car to drive the front wheels with the engine up there too.

 

Found a good comparison of the most common GM variant T56 lengths for reference (numbers on the right, the left has a dimensioning error). A little shorter than Id guessed, but keep in mind this is without driveshaft or rear end (or an adapter plate to actually bolt it up to a LS4)


You can pop your hood, put a tape measure against the back of the block and walk it 33" out of the driver's side. You'll see what I mean by fitment being 'problematic' (that's also completely ignoring the fact of the output shaft being all the way at the far end of that thing facing away from the car). It's just flat out not meant for FWD applications.