Hello, I have a plethora of issues with my LT-1 and have the money to just replace it with a much more powerful motor. I’m looking at purchasing a crate motor. my question is will any “350” or “383” crate motor fit? And will it bolt into my transmission. my understanding is the the C4 is built for a 350. So a 350 should fit regardless of which 350. Would replacement 350 motor mounts fit? if I am wrong about any of this. How do I make sure an engine will fit and be compatible?
if any of these questions seem ignorant please forgive me.
thank you!

 

any chevy small block will fit with ease.

 

thank you, now what about wiring harness? Will a LT1 wiring harness fit? Or perhaps just a “generic 350 wiring harness”. and would I have to replace my ECM.
again thank you and anyone else with helpful info, I am the kind of person that must know every detail before I follow through. Unfortunately the resources for a c4 swap are a little limited. So I’ve come here for help.

 

unless you want to start changing things it's exactly that. depending on how much more horsepower the new motor makes some fine tuning to the ecm might be helpful.

 

The short answers are:
Yes. No.
Provided the replacement crate engine is an LT and not an LS.

 

The engine I'm looking at is the “wise guy” 383 stroker made by west coast engines.

 

I would go with LS3, lot more power you will ever need, 430 HP!

 

Chad builds a bad mamma jamma , price is right , pro built forged everything. Mine makes 514 /493 dynoed and shipped . It makes a bit more after a throttle body swap ( my choice thanks Mark aka mr. Peabody . I spray 200 and she doesn’t blink . Chad said it will hold a bunch more !! Pro built great process !



Peek a boo , I did the fancy work , hoses , alternator , pump ect and the custom air intake , but Chad ships what ever color you want . Hope it helps . GOD bless Robert , PS we are thinking 10s come this spring !!!

 

Considering he asked for something that wounder be drop in and compatible with everything that's there... probably not the easiest route... for power however, it is.

 

My 6.0 makes about 500 hp and it isn't enough. I still need more power.

 

Cant use a Gen 1 with your LT car. Ck with Golen

 

Yeah my LS6 makes around 450 and the new 6.0L that's going in soon will make 500 without the nitrous. I think the 6.0L or even a 5.3L with a cam would get the job done. Me personally I would avoid the LS3. The price of the motor just isn't worth it in a street car.

 

Based on the OP's questions, I don't think it is advisable for him to do anything except get an exact replacement for his engine or rebuild it and leave it alone. All of you who are replying need to go back and reread the first post. I'm not trying to be an a-hole, but he doesn't know enough to know what he doesn't know, you know? Any kind of significant power upgrades - even from an LT-based replacement - will require other changes, including a recalibration of the ECM/PCM (depends on which year car he has as to which kind of computer he has). If you have to ask if a 383 crate motor "will fit" in a C4, you should not be trying to make big modifications!

Not too mention, you don't fix "a plethora of problems" with an LT1 by swapping motors. Unless it has sent a rod through the block, you find and fix the problems and maybe (if it has bad rings or bearings or something else internal) you pull it and rebuild it. All you guys recommending LS swaps and other major power upgrades are going to lead the OP into spending lots of money to ensure that his car never runs again.

ETA: To the OP, your questions are completely fine and you don't need forgiveness. It's good that you're asking them. They do show that you're at the base of a very steep learning curve. Again, that's nothing to be ashamed of or ask forgiveness for. You should keep asking questions: that's why this forum exists! I'm just trying tell the others here that they are leading you into water that's way over your head right now.

 

That's not really true anymore. An LS simply costs less then an LT1 at the same power level. A junkyard 5.3L with a cam will make 400 hp all day long. To build a LT1 that will do that would cost a lot more. That's why we do LS swaps. From a cost perspective you can't beat them. If you drop the .bin file in yourself from either PCM Hammer or HP Tuners and you don't mind modifying a truck harness yourself then an LS swap can be done for sub $1k.

But that aside if the OP wants to keep the car more original by using the same family of engine as it had factory I can respect that. But it will cost him more without a doubt.

 

Doesn sound like he may have those abilities (could be wrong).
Its gonna cost a fortune to have a shop do that....and personally I wouldnt want a 290hp junkyard engine?
350 has more cubes to start with the 5.3 heads arent anything special.
You know how to do it yourself, brackets, wiring etc maybe engines are cheap where you are
No junkyard out this way (socal) will sell a 5.3 for less than 13-1500
He can get a Maabco long block for not much more

 

It does depend on where you live. I just bought 2 LQ4 6.0Ls with 4L80's for $250 each. They both have 150K miles on them. I can get an aluminum 5.3L with 243 heads for $300 with the harness. I would rather get a low mileage 5.3L and put in a cam to get to 400hp then buy/build a crate motor. But everyone is different. I would recommend checking out these guys here. They are a franchise and have multiple locations across the country. I have had a business account with them for a few years now. But anyone off the street can go in on a sale day and get a great deal on a low mileage engine with a warranty.

But I completely agree that it would cost a fortune to have a shop do it. But it would cost a fortune to have a shop swap in any motor. That's why I would do the work myself. If you can't then I would learn.

 

This is all just ridiculous. You're going to "drop the .bin file from PCM Hammer or HP Tuners" into what? Not into any C4 ECM/PCM, that's for damn sure. And when you put the LS ECU into the C4, how will you integrate it into the dash? And how will you bolt the LS to a stock ZF6 or 700r4 or 4L60E, or bolt a T56 to the C-beam? And what will you do for accessory drives? And so on...

It's not that these things can't be done - they have been. But they aren't free unless you can do all the labor yourself...and we're talking about a guy who is asking if a 383 will fit in the same space as a 350. Never. Gonna. Happen.

Besides all that, anybody can make 400hp from a gen-II LTx engine with just a cam kit and some cheap heads. That's easy and far cheaper than any LS swap. If I did all the work and/or expense of an LS swap into a C4 and only got 400hp, I'd kill myself.

 

Look, everyone has there opinion. When I mentioned about dropping the .bin file you would need to drop the file into the LS PCM to make it stand alone. The files are already done for you on the HP Tuners repository. Then you would need to wire the dash using the original sensors. I went with aftermarket gauges but lots of people here have done an LS swap with the factory cluster.

Even if you went with an aftermarket ECU like I did it's less costly then a crate 383 or really any crate LTx. Think about it, $1400 for a Holley Terminator X Max system, $500 at most for a low mileage LS motor, $300 for a Summit cam, $100 for springs. So under $2500 you get touch screen fuel map control with self tuning and a wide band O2. If you chose an LQ9 for your base engine you're over 500 hp. I have no concept as to way anyone would build or buy an LT motor today for a street car when the technology is so much better in the LS world. As far as bolting everything up goes you can use the factory transmission. It has been well documented on this forum. In most cases you will need an aftermarket flex plate. I recommend getting the transmission with the engine however. I just put a $200 4L80e in my 84 that was pulled from a 2009 Express van. Yes I had to fabricate a C beam adapter. But I learned how to do that from this forum. I even made a YouTube video about it

 

I don't understand why this always becomes a pissing match and that you're an idiot for doing x or y.

 

I'm not discussing opinions - I'm discussing facts. For example, you can't just bolt an LS to a stock C4 transmission. To do a ZF6, you need an expensive adaptor (and a different input shaft) or aftermarket bellhousing (and I think even that needs machining after you spend $800 on it). You can't just bolt a late-model transmission into a C4: you have to fabricate a C-beam mount. You can't just "wire the dash using the original sensors," because in some cases the dash gauges and functions are run by the CCM, which gets some of its inputs from the stock PCM, which you are no longer using. An aftermarket dash is great, and that's probably how I'd do it, but again we're talking money and fabrication work. Want to keep functional a/c? Hmmmm.

These things can absolutely be accomplished, and they have (as you noted). I'm not saying they can't. I'm saying you can't just buy $2500 of parts and have this all done in a day like you could with a drop-in LT1 replacement engine. Either you will have to do serious fabrication work yourself or you'll have to pay a metric ****-ton of money for someone else to do it all for you. Again we are talking an OP who doesn't know if/how various generation small blocks are different from each other and wonders if the engine's displacement affects how it fits in the car. Do you honestly think he's ready to take on an LS swap into a C4?! Can't we just be honest and acknowledge that he's not? We would be doing him a lot more good by delving into what's really wrong with his current engine and diagnosing that so it could be fixed or advising him on a drop-in replacement or rebuild if it's really at that point.


It's not a pissing match and nobody called anybody an idiot for choices they made in upgrading their own cars. This isn't about that. This is about advising a neophyte that he should aim for a major power upgrade just because he has some issues with his current engine, and advising him that he can and should go about it by doing an LS swap and misleading him into thinking it's easy and cheap. It is neither of those things. You can do projects like this without spending a bunch of cash if you really know how to fab and customize things and you don't count your labor as an expense. But in this case... Don't know how to cut/fab/weld metal? SOL. Don't know how to wire a car? SOL. Don't know how to open your dash and replace it with an aftermarket unit? SOL. Don't even know what displacement means or anything about the various generations of Chevy small blocks? Really SOL! All those SOLs add up to the OP either having a car that never runs again after he buys a few thousand dollars worth of parts, or him paying biiiiiiiiiig money to someone else to do all the required work. There's no bolt-in kit. It just doesn't work that way. I know professionals that do these swaps for a living, and they will flat-out tell people they are on crack if they think you can do a swap like for the super-cheap costs people like to throw around. There are big threads on this forum that detail LS C4 projects. Anyone who thinks you can just plunk an $500 LS into a C4 and end up with a way faster C4 where all the features still work will be disavowed of that belief after a little research.