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Lr4 4.8 vs Lm7 visuals?

 
Old 06-10-2019, 03:12 PM
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Default Lr4 4.8 vs Lm7 visuals?

Hey guys! So gonna register my truck in sweden with the new engine and tranny. We have fucked up laws here so I cant say its the 2003 Lm7 thats acutally in the car since we can only increase the hp with 20% from stock engine.
But then I found out that the 1999 Lr4 only had 255hp.?
Is there any way to tell if its a 4.8 or a 5.3 just looking at the engine?
And you know if there was or what car in 1999 had the Lr4 with 4l60e tranny?
Thanks!
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Old 06-10-2019, 09:37 PM
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Only trucks had the LR4 or any Gen III 5.3 or 4.8 for that matter. And no, there is NO visible difference between the two since the only real difference is the stroke. Same block and everything else external. So call it an LR4. Only you will know.
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Old 06-10-2019, 11:15 PM
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Originally Posted by G Atsma View Post
Only trucks had the LR4 or any Gen III 5.3 or 4.8 for that matter. And no, there is NO visible difference between the two since the only real difference is the stroke. Same block and everything else external. So call it an LR4. Only you will know.
Great! So a 1999 1500 silverado had the lr4 and 4l60e? =) but isnt there some casting number on the blocks of these engines?
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Old 06-11-2019, 12:14 AM
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Originally Posted by Robin86 View Post
Great! So a 1999 1500 silverado had the lr4 and 4l60e? =) but isnt there some casting number on the blocks of these engines?
The casting number shows ď4.8/5.3Ē on both since itís the same block for both engines

lm7 does have a dished piston instead of a flattop but from the outside thereís no way to tell
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Old 06-11-2019, 12:37 AM
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Originally Posted by 1988montecarloss View Post
The casting number shows ď4.8/5.3Ē on both since itís the same block for both engines

lm7 does have a dished piston instead of a flattop but from the outside thereís no way to tell
Awesome! And the casting numbers are hard to see when engine is in car if I get it right? Since my engine is a 2003 and the engine im gonna tell the register is in the car is a 1999
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Old 06-11-2019, 01:26 AM
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They will never know the difference.
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Old 06-11-2019, 09:24 PM
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Originally Posted by Robin86 View Post
Awesome! And the casting numbers are hard to see when engine is in car if I get it right? Since my engine is a 2003 and the engine im gonna tell the register is in the car is a 1999
Yeah itís on the front and rear about halfway down the cylinder bore, the accessories and flexplate cover it up
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Old 06-11-2019, 11:50 PM
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The year won't make any difference since BOTH the LR4 and the LM7 were built from 1999 to about 2007. Only thing you need to convince the authorities is that the engine is a 4.8. It can be a 2003 4.8 if the year does not matter.
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Old 06-12-2019, 12:02 AM
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Originally Posted by G Atsma View Post
The year won't make any difference since BOTH the LR4 and the LM7 were built from 1999 to about 2007. Only thing you need to convince the authorities is that the engine is a 4.8. It can be a 2003 4.8 if the year does not matter.

Ok =) well the 1999 4.8 was the Only one with 255hp. After that it had 270-280 if I can remember correctly and thats more then a 20% increse from stock engine so wont work. =/ But I guess and hope he cant see the block numbers lol
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Old 06-12-2019, 12:20 AM
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No, as long as a transmission is bolted up and a front accessory drive installed, he wont see a thing.
The power rating difference is weird because there is NO difference in parts between higher or lower rated versions. Same cam, heads, etc.

Last edited by G Atsma; 06-12-2019 at 12:29 AM.
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Old 06-12-2019, 12:34 AM
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Originally Posted by G Atsma View Post
No, as long as a transmission is bolted up and a front accessory drive installed, he wont see a thing.
The power rating difference is weird because there is NO difference in parts between higher or lower rated versions. Same cam, heads, etc.
Yup everything is stock but the headers and air intake so fingers crossed hehe. Yeah, well as long as it says 255 hp on google im happy lol, 258 is the max hp I can register with lol
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Old 06-12-2019, 08:32 AM
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Originally Posted by Robin86 View Post
Yup everything is stock but the headers and air intake so fingers crossed hehe. Yeah, well as long as it says 255 hp on google im happy lol, 258 is the max hp I can register with lol

Do they dyno you car to check the power output? im sure there are MANY ways to get around that. .. throttle stop? load a crappy tune?
or do you just tel them what engine it is and they go by that?
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Old 06-12-2019, 08:56 AM
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Originally Posted by Ls7colorado View Post
Do they dyno you car to check the power output? im sure there are MANY ways to get around that. .. throttle stop? load a crappy tune?
or do you just tel them what engine it is and they go by that?

No dyno thankfully hehe. I guess they would like to have some sort of block numbers or maybe a donor vin but im hoping I can get around it somehow lol
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Old 06-12-2019, 04:19 PM
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The 99’ engine will have come from GM with a return fuel system, meaning visually there will be a return fuel line on the intake, and FPR is on the intake also. Be prepared to have a story for this if you don’t have a return fuel system on the vehicle at this point.
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Old 06-12-2019, 04:49 PM
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Which car is this engine in? Use this story- "I had to adapt the fuel system to a returnless so it would work in the truck. Otherwise it's an original 1999 4.8L Chevy truck engine. That's the truth as far as you know..."

Last edited by G Atsma; 06-13-2019 at 12:23 AM.
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Old 06-13-2019, 12:13 AM
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Originally Posted by Che70velle View Post
The 99í engine will have come from GM with a return fuel system, meaning visually there will be a return fuel line on the intake, and FPR is on the intake also. Be prepared to have a story for this if you donít have a return fuel system on the vehicle at this point.
Alright didnt know that. Thanks! The engine sits in s 69 F100. Did 1999 silverado have this engine?
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Old 06-13-2019, 12:24 AM
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4.8 and 5.3 Gen III engines came ONLY in trucks like Silverados, Tahoes, Suburbans, and full size vans (and GMC and Cadillac equivalents). They never were put in cars.
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Old 06-13-2019, 01:36 AM
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=) new to these engines so sorry if I ask dumb questions lol
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Old 06-13-2019, 05:08 AM
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In 1999 the Lr4/4l60e combo was only available in the Silverado 1500.
If the ECM has programming from a vehicle with a 5.3 Vin, which is
accessed through the OBD2 port, it might raise suspicions. Also, headers
and a cold air intake does not reinforce the premise that the engine is stock.

Last edited by 88bruce; 06-13-2019 at 05:35 AM.
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Old 06-13-2019, 05:47 AM
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Originally Posted by 88bruce View Post
In 1999 the Lr4/4l60e combo was only available in the Silverado 1500.
If the ECM has programming from a vehicle with a 5.3 Vin, which is
accessed through the OBD2 port, it might raise suspicions. Also, headers
and a cold air intake does not reinforce the premise that the engine is stock.
This is why I was asking how they verify what engine he actually has....
Why so many rules? if you can only add 20% over stock power, can you do weight reduction?
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