Lr4 4.8 vs Lm7 visuals?
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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!
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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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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Great! So a 1999 1500 silverado had the lr4 and 4l60e? =) but isnt there some casting number on the blocks of these engines?
lm7 does have a dished piston instead of a flattop but from the outside there’s no way to tell
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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 it’s on the front and rear about halfway down the cylinder bore, the accessories and flexplate cover it up
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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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Teching In
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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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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.
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; Jun 12, 2019 at 12:29 AM.
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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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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
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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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; Jun 13, 2019 at 12:23 AM.
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Alright didnt know that. Thanks! The engine sits in s 69 F100. Did 1999 silverado have this engine?
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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.
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; Jun 13, 2019 at 05:35 AM.
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.
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.
Why so many rules? if you can only add 20% over stock power, can you do weight reduction?