# LT1 5.7Liter and 4.3Liter



## whookidd

Hey,

I have a question I have a 1994 caprice and the engine was replaced before I bought it. Well a lot people are telling me I have a 5.7liter. But on the title it says 4.3liter. How can you tell the difference between the 2 type of engine?


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## lil6yplayboy

one is v8 other is 6 banger...


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## 509Rider

> _Originally posted by lil6yplayboy_@May 31 2007, 10:12 PM~8019730
> *one is v8 other is 6 banger...
> *


Ya but they put a 4.3 v8s in alot of caprices, they look exactly like an lt1.


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## avengemydeath

> _Originally posted by 509Rider_@May 31 2007, 11:16 PM~8019778
> *Ya but they put a 4.3 v8s in alot of caprices, they look exactly like an lt1.
> *


uh, i never heard of this one.


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## avengemydeath

> _Originally posted by whookidd_@May 31 2007, 10:54 PM~8019563
> *Hey,
> 
> I have a question I have a 1994 caprice and the engine was replaced before I bought it. Well a lot people are telling me I have a 5.7liter. But on the title it says 4.3liter. How can you tell the difference between the 2 type of engine?
> *


could be a typo, the 94 caprice should come witha LT1(V8).  4.3liter is a V6.


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## lil6yplayboy

> *could be a typo, the 94 caprice should come witha LT1(V8).  4.3liter is a V6.*



Indeed thats what i was saying.. I never seen a 4.3 v8...lol..but you never know these days.

i think the 94 had just the plain gm 350 in it not the lt1 but i may be wrong..


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## 509Rider

> _Originally posted by avengemydeath_@May 31 2007, 10:18 PM~8019801
> *uh, i never heard of this one.
> *


They make them, trust me they look exactly like an lt1 and most people that have them think they are an lt1.


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## 509Rider

1995 Chevrolet Caprice Performance

* 4,312 cc 4.3 liters 8 V 90? front longitudinal engine with 94.9 mm bore, 76.1 mm stroke, 9.8 compression ratio, cast iron block, cast iron head, overhead valve and two valves per cylinder
* Unleaded fuel
* Fuel economy EPA highway (l/100km): 9
* Multi-point injection fuel system
* 87 liter fuel tank
* Power: SAE and 149 kW , 200 HP @ 5,200 rpm; 235 ft lb , 319 Nm @ 2,400 rpm


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## RIVERSIDELOWRIDING

ONE HAS DUAL EXAUST THE OTHER HAS SINGLE..ONE IS FAST THE OTHER IS DOGG SHIT, ONE EATS GAS TO GO FAST THE OTHER JUST EATS THE GAS TO PUT A DENT IN YOUR WALLET.... SEND ME A PIC OF IT...


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## whookidd

> _Originally posted by 509Rider+May 31 2007, 10:33 PM~8019935-->
> 
> 
> 
> 1995 Chevrolet Caprice Performance
> 
> * 4,312 cc 4.3 liters 8 V 90? front longitudinal engine with 94.9 mm bore, 76.1 mm stroke, 9.8 compression ratio, cast iron block, cast iron head, overhead valve and two valves per cylinder
> * Unleaded fuel
> * Fuel economy EPA highway (l/100km): 9
> * Multi-point injection fuel system
> * 87 liter fuel tank
> * Power: SAE and 149 kW , 200 HP @ 5,200 rpm; 235 ft lb , 319 Nm @ 2,400 rpm
> [/b]
> 
> Click to expand...
> 
> Yeap that is the one I have. It does look just like a LT1. But I need to know which one I really do have. Isnt there a way to check and see?
> 
> <!--QuoteBegin-RIVERSIDELOWRIDING_@May 31 2007, 10:52 PM~8020079
> *ONE HAS DUAL EXAUST THE OTHER HAS SINGLE..ONE IS FAST THE OTHER IS DOGG SHIT, ONE EATS GAS TO GO FAST THE OTHER JUST EATS THE GAS TO PUT A DENT IN YOUR WALLET.... SEND ME A PIC OF IT...
> *


 Well my car has dual exhaust. I will send you a picture as soon as I get home.


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## Badass94Cad

> _Originally posted by avengemydeath_@Jun 1 2007, 12:19 AM~8019811
> *could be a typo, the 94 caprice should come witha LT1(V8).   4.3liter is a V6.
> *


No, a 94 Caprice would come with an L03 (350 V8) or a 4.3 V8. The 4.3 V6 is an S-10 engine, completely different. The 9C1 (Police) Caprice came with the LT1.

The easiest way to tell if you have an LT1 without looking at the engine code is to hit the gas. If it goes like stink (260 HP), you got an LT1. If it's dog slow (135 HP, or thereabouts), you have a 4.3.


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## joe64ss

Check the casting numbers on the block on the drivers side rear near the bellhousing and go to www.mortec.com

Casting 10168588 - 265 C.I. 94-96 L99, Gen.II, 4.3 Liter V-8, Caprice, reverse flow cooling


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## whookidd

> _Originally posted by joe64ss_@Jun 1 2007, 02:05 PM~8023897
> *Check the casting numbers on the block on the drivers side rear near the bellhousing and go to www.mortec.com
> 
> Casting 10168588 - 265 C.I. 94-96 L99, Gen.II, 4.3 Liter V-8, Caprice, reverse flow cooling
> *


Thank you alot. I will check I just need a mirror and a flashlight.


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## whookidd

> _Originally posted by RIVERSIDELOWRIDING_@May 31 2007, 10:52 PM~8020079
> *ONE HAS DUAL EXAUST THE OTHER HAS SINGLE..ONE IS FAST THE OTHER IS DOGG SHIT, ONE EATS GAS TO GO FAST THE OTHER JUST EATS THE GAS TO PUT A DENT IN YOUR WALLET.... SEND ME A PIC OF IT...
> *


Here are some pictures.


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## SLIMONTHABUMPERRRRRR

i have a 4.3 in mine and yes it looks like the lt1 5.7 dosent make as much power if the vin has a W in the first 6 somewhere then it has the 4.3 and it is a v8 with a smaller bore and stroke i think


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## whookidd

> _Originally posted by SLIMONTHABUMPERRRRRR_@Jun 2 2007, 07:16 PM~8029951
> *i have a 4.3 in mine and yes it looks like the lt1 5.7 dosent make as much power if the vin has a W in the first 6 somewhere then it has the 4.3 and it is a v8 with a smaller bore and stroke i think
> *


DO you know where the vin is? what year is your car? do you have pics? do you know where I can go to upgrade the engine to give it more horsepower?


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## CHELADAS75

check the vin code. its the 8th digit from left to right.


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## avengemydeath

that looks like a LT1 to me. Look at the manifold. I never heard of a 4.3 V8. wow


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## cashmoneyspeed

Wow, lots of misinformation in this thread. A 1994 Caprice would come with the L99 4.3 or the LT1 5.7 ONLY from the factory. The Lt1 5.7 L V8 looks exactly the same as the L99 4.3L V8. The LT1 has 260 hp and dual exhaust from the factory. The L99 has much less and single exhaust from the factory. Only way to tell by looking is by the casting #'s or measuring internal engine components. Also the manifold's are the same. There are a lot of civilian built caprice's with the 5.7L in them as well but there will be a sound deadener on the firewall and usually but not always a mechanical fan rather then electrical like what's found on those that were built for municipalities and the 94-96 impala SS.  


Try this, start the car, put it in gear and put the pedal to the floor. What happened? Did you peel out with both rear tires or just sort of lurch forward?


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## whookidd

> _Originally posted by cashmoneyspeed_@Jun 2 2007, 10:59 PM~8031084
> *Wow, lots of misinformation in this thread. A 1994 Caprice would come with the L99 4.3 or the LT1 5.7 ONLY from the factory.  The Lt1 5.7 L V8 looks exactly the same as the L99 4.3L V8.  The LT1 has 260 hp and dual exhaust from the factory.  The L99 has much less and single exhaust from the factory.  Only way to tell by looking is by the casting #'s or measuring internal engine components. Also the manifold's are the same.  There are a lot of civilian built caprice's with the 5.7L in them as well but there will be a sound deadener on the firewall and usually but not always a mechanical fan rather then electrical like what's found on those that were built for municipalities and the 94-96 impala SS.
> Try this, start the car, put it in gear and put the pedal to the floor.  What happened?  Did you peel out with both rear tires or just sort of lurch forward?
> *


Nope I did not peel out, it just lurch forward. I tried to peel out plenty of times but it doesnt do it. I have the regular spark plugs as well because I assumed I had a 4.3liter. So it is safe to say I have a 4.3liter?


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## cashmoneyspeed

Regular spark plugs???? I don't know what you mean by that but here's another tip, i use NGK TR55 spark plugs on every caprice that i get or have changed plugs on due to their heat range and the fact that i drive bubbles like i stole em. Do you have single or dual exhaust? and if it's dual, is it dual all the way from the cats or are the pipes welded together towards the front of the car and then split into 2 pipes?


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## whookidd

> _Originally posted by cashmoneyspeed_@Jun 3 2007, 12:31 AM~8031421
> *Regular spark plugs????  I don't know what you mean by that but here's another tip, i use NGK TR55 spark plugs on every caprice that i get or have changed plugs on due to their heat range and the fact that i drive bubbles like i stole em.  Do you have single or dual exhaust?  and if it's dual, is it dual all the way from the cats or are the pipes welded together towards the front of the car and then split into 2 pipes?
> *


I mean I use store spark plugs cheap ones. I have dual exhaust. Yes they are straight from the cats.


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## ALLslowNOshow

Since your motor was replace, the sire fire way to know what you have is to check the casting numbers on the block, since the L99 and the LT1 are visually the same. Another way to check what motor you had originally is to check the SPID label with is located under your trunk lid and it looks like this:









As you can see in this pic it has a LT1 listed in it, if you had the L99 it would list that instead.

I know with my LT1 Caprice it doesn't really spin the tires, I guess the 275 tires all around and 173k miles on the motor doesn't help much, lol.


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## whookidd

> _Originally posted by ALLslowNOshow_@Jun 4 2007, 03:39 AM~8037125
> *Since your motor was replace, the sire fire way to know what you have is to check the casting numbers on the block, since the L99 and the LT1 are visually the same. Another way to check what motor you had originally is to check the SPID label with is located under your trunk lid and it looks like this:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> As you can see in this pic it has a LT1 listed in it, if you had the L99 it would list that instead.
> 
> I know with my LT1 Caprice it doesn't really spin the tires, I guess the 275 tires all around and 173k miles on the motor doesn't help much, lol.
> *


OK thanks I will check it out.


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## Juiced82MarkVI

it must be a 4.3.... nobody would put blue wire loom on an LT-1 =x


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## cashmoneyspeed

Also, G80 on the SPID code would mean you have a posi traction rear end which most likely indicates having the LT1 motor.


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## whookidd

> _Originally posted by cashmoneyspeed_@Jun 5 2007, 11:54 PM~8050595
> *Also, G80 on the SPID code would mean you have a posi traction rear end which most likely indicates having the LT1 motor.
> *


OK cool, well I am giving up this car. Thank you all for your help. It is a 4.3 liter.


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## Cali-Stylz

Not the same topic but who here spends enough time under their ride to know how many catalitic converters the Cadillac Fleetwood LT1 5.7. Mine seem to have fallen off and grew straight pipe in its place :biggrin: Now I have to put it/them back so that I can pass California's emission standards hno:


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## concrete

> _Originally posted by Cali-Stylz_@Jun 11 2007, 07:40 PM~8085476
> *Not the same topic but who here spends enough time under their ride to know how many catalitic converters the Cadillac Fleetwood LT1 5.7. Mine seem to have fallen off and grew straight pipe in its place  :biggrin: Now I have to put it/them back so that I can pass California's emission standards  hno:
> *



To my knowledge you would have 2 as long as you have duel pipes from front to back. 

Mufflers and resonators would be nice too if you don't like it loud...


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## cashmoneyspeed

> _Originally posted by Cali-Stylz_@Jun 11 2007, 08:40 PM~8085476
> *Not the same topic but who here spends enough time under their ride to know how many catalitic converters the Cadillac Fleetwood LT1 5.7. Mine seem to have fallen off and grew straight pipe in its place  :biggrin: Now I have to put it/them back so that I can pass California's emission standards  hno:
> *


2 cats homie, hopefully those "test pipes" didn't weld themself on because if they still have the stock style flanges, you can just swap some cats back in for the time being.


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## purplemonte

easiest way to tell- check code on back of block by bellhousing like suggested. if you cant see it, look on passenger side of block. youll probably have to get under the car. on the side of the block above the oil pan look for the numbers 327. if it says 327, its an lt1, not the l99


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## cashmoneyspeed

You can see if there are 2 cats from under the hood, just look at what's after the exhaust manifolds. 94-95will have 2 oxygen sensors and 96 will have 4 o2 sensors all together unless you have o2 simulators for the rear sensors.


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## Cali-Stylz

> _Originally posted by concrete+Jun 11 2007, 07:58 PM~8086229-->
> 
> 
> 
> To my knowledge you would have 2 as long as you have duel pipes from front to back.
> 
> Mufflers and resonators would be nice too if you don't like it loud...
> [/b]
> 
> Click to expand...
> 
> It is stock, have not changed anything (means two cats right)....well, other than the cats :biggrin: I just need to get it to pass smog, which will not be a problem when it grows the cats back
> 
> <!--QuoteBegin-cashmoneyspeed_@Jun 12 2007, 08:53 PM~8093782
> *2 cats homie, hopefully those "test pipes" didn't weld themself on because if they still have the stock style flanges, you can just swap some cats back in for the time being.
> *


Nope, they grew in the right way (welds). Its not a problem to have someone throw the new one's in...just want to be sure I get two if they are both needed. 

SECOND QUESTION:

Uh :uh: Do you guys happen to know what size the factory exhaust pipe is :biggrin: Cats on Ebay but gotta order the right size.


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## Cali-Stylz

> _Originally posted by concrete+Jun 11 2007, 07:58 PM~8086229-->
> 
> 
> 
> To my knowledge you would have 2 as long as you have duel pipes from front to back.
> 
> Mufflers and resonators would be nice too if you don't like it loud...
> [/b]
> 
> Click to expand...
> 
> It is stock, have not changed anything (means two cats right)....well, other than the cats :biggrin: I just need to get it to pass smog, which will not be a problem when it grows the cats back
> 
> <!--QuoteBegin-cashmoneyspeed_@Jun 12 2007, 08:53 PM~8093782
> *2 cats homie, hopefully those "test pipes" didn't weld themself on because if they still have the stock style flanges, you can just swap some cats back in for the time being.
> *


Nope, they grew in the right way (welds). Its not a problem to have someone throw the new one's in...just want to be sure I get two if they are both needed. 

SECOND QUESTION:

Uh :uh: Do you guys happen to know what size the factory exhaust pipe is :biggrin: Cats on Ebay but gotta order the right size.


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