# Engine swapping my 71 Chevy Monte Carlo



## Givingwolf (Oct 14, 2021)

Hey all,

I was just wondering if it was possible at all to take a 455 from the 68 gto I have and swap that into my 71 Chevrolet Monte Carlo? I know that I will need a new transmission which I’m planning on converting it to a manual, I also want to put in a posi rear end. My only concern is the headers might not for into the engine bay.


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## armyadarkness (Dec 7, 2020)

The year is relatively irrelevant. You could put that 455 into most any GM car, which came with a factory V8, as well as several which didn't. You'll need a BOP Transmission or bell housing to go with it (which you already know), but everything else will be largely the same.


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## armyadarkness (Dec 7, 2020)

The headers will work fine, but Pontiac headers SUCK OUT LOUD to install.


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## armyadarkness (Dec 7, 2020)

Youll just buy Pontiac headers for a Grand Prix.


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## armyadarkness (Dec 7, 2020)

BTW, although it's an A body, the frame is not the same. But that's not relevant to what youre trying to do. You can use a chevy or BOP rear. I'd probably just add an Auburn diff to whatever you have


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## Givingwolf (Oct 14, 2021)

armyadarkness said:


> The headers will work fine, but Pontiac headers SUCK OUT LOUD to install.


the 455 that I’m going to try and put in the Monte is already fully built and has Doug headers on it. But I definitely agree pontiac headers do suck to install. But I’m concerned because their isn’t much room down by the control arm area I’m pretty sure it’ll work but if not then I guess I gotta just sell the engine haha


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## Givingwolf (Oct 14, 2021)

armyadarkness said:


> BTW, although it's an A body, the frame is not the same. But that's not relevant to what youre trying to do. You can use a chevy or BOP rear. I'd probably just add an Auburn diff to whatever you have


Yeah I just learned that it’s called a G-body I don’t think that it would matter or not


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## Givingwolf (Oct 14, 2021)

armyadarkness said:


> The year is relatively irrelevant. You could put that 455 into most any GM car, which came with a factory V8, as well as several which didn't. You'll need a BOP Transmission or bell housing to go with it (which you already know), but everything else will be largely the same.


Do you know if the mounts are in the same place? Like is it just a drop it in then bolt it then go or what will I have to get to put that in?


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## O52 (Jan 27, 2019)

You need Grand Prix frame and motor mounts


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## armyadarkness (Dec 7, 2020)

Givingwolf said:


> the 455 that I’m going to try and put in the Monte is already fully built and has Doug headers on it. But I definitely agree pontiac headers do suck to install. But I’m concerned because their isn’t much room down by the control arm area I’m pretty sure it’ll work but if not then I guess I gotta just sell the engine haha


I would ditch the headers if it doesnt fit, and go with Ram Air manifolds. The headers dont add much more power and theyre WAY worse to deal with. However, it'll likely fit fine since that is the way it is in a GTO as well.


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## 66COUPE (Jul 23, 2021)

So you have a 68 GTO and want to put the 455 motor into a 71 monte, neither of which is stock. Go with your choice. 👍


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