LH6 Advice
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LH6 Advice To start with, I’m very familiar with old SBC, but I’m new to the LS world. I’m hoping you guys can offer some advice. I’ve got an 06 Envoy Denali with an LH6 5.3 that threw a rod. I picked up an 08 LH6 out of an Envoy Denali to replace it. I’d like to bump the hp 75-100 hp. The vehicle will be a daily driver and I’m somewhat on a budget. I looking for a recommended cam. Also, should I delete the AFM? Can anyone recommend a tuner service to whom I can send the ecm? I have the ECM from the 08. TIA for the help!
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There's one glitch with replacing an 06 LH6 with an 08 LH6. The 06 has the 24x crank reluctor, sensor and ECM, while the 08 has the 58x system. They are 2 different ECM's with 2 different crank reluctors. You can't just drop one engine in place of the other, it's not plug and play.
There's one glitch with replacing an 06 LH6 with an 08 LH6. The 06 has the 24x crank reluctor, sensor and ECM, while the 08 has the 58x system. They are 2 different ECM's with 2 different crank reluctors. You can't just drop one engine in place of the other, it's not plug and play.
Edit...it’s a crossover engine. I’m wrong.
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There's one glitch with replacing an 06 LH6 with an 08 LH6. The 06 has the 24x crank reluctor, sensor and ECM, while the 08 has the 58x system. They are 2 different ECM's with 2 different crank reluctors. You can't just drop one engine in place of the other, it's not plug and play.
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Yep, by the way things "should" be. My 05 LH6 is a bastard lol. I thought I had an L33 until I realized it had 799 heads, front cover mounted crank sensor, and 24x.
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05-06 are 24x, 07-09 are 58x, according to the above source
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In my personal opinion, delete the AFM. Summit has a nice line of off the shelf LS cams and are pretty knowledgeable about helping you decide which one to go with based off your needs. IIRC the 06/07 Envoy denalis had the E40 PCM which seems to be one of the preferred options for tuning.
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Getting 75 horsepower isn't a big deal with just a cam, but you have to realize that it isn't going to idle the same or get the same fuel economy.
There have been probably 100+ dyno comparisons for cams in a 5.3, it should be fairly easy to find them.
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The only one of those that isn't a feature of the L33 is the cover mounted sensor.
Definitely delete the AFM.
Getting 75 horsepower isn't a big deal with just a cam, but you have to realize that it isn't going to idle the same or get the same fuel economy.
There have been probably 100+ dyno comparisons for cams in a 5.3, it should be fairly easy to find them.
Definitely delete the AFM.
Getting 75 horsepower isn't a big deal with just a cam, but you have to realize that it isn't going to idle the same or get the same fuel economy.
There have been probably 100+ dyno comparisons for cams in a 5.3, it should be fairly easy to find them.
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Google "5.3 cam comparison". You'll find tons of articles and tests. You should be able to spot the ballpark cam specs you need to get the gains you want, then you can shop around.
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According to summits LS identification tool, the L33 shouldn't have 799 heads. Is it mistaken? I keep finding conflicting information. My engine came out of a 2005 GMC Envoy Denali 2wd standard wheelbase. Which by everything GM says it should be an L33.
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799 and 243 are the same except for casting method, but I think you're right. I doubt 799's came out before Gen IV engines did. I would bet they came out because that type (243/799) of head would be used on every 4.8/5.3 Gen IV made, so more mfg. volume was needed. Hence the 799.
I have an L33. It has 799 heads on it.