Odd questions about LQ4 before swapping
Thread Starter
Racer
Joined: Oct 2005
Posts: 426
Likes: 72
From: B-town Idaho
Odd questions about LQ4 before swapping
I have a 75 vette, 4 speed, l48, 3.36 rear end.
I recently was able to purchase a 99 Silverado 2500 LQ4 6.0L, 5 speed manual(nv4500). From all that I've been able to find, is that the first two years of the 6.0L in trucks had too long of a crank to fit a T56 behind it and something about no aftermarket flywheels that will work. What I can't find is any information on my specific truck. Everyone's "long crank" comments are dealing with the 4l80 trans. But, I'm not sure if all of the engine in 99 had long cranks, since mine is a manual. So, a few questions that I cannot find the answers to:
1. Have any of you built a swap engine from this era of truck? if so, mated it to a 6 speed? if so, what steps do I need to take?
2. if mine does have the long crank and it won't work as is, can I purchase a short crank for it or is the difference in the casting of the block?
3. anything else I should keep my eye on?
overall, just wondering if I should sell the truck before I do an entire engine rebuild with it.
I recently was able to purchase a 99 Silverado 2500 LQ4 6.0L, 5 speed manual(nv4500). From all that I've been able to find, is that the first two years of the 6.0L in trucks had too long of a crank to fit a T56 behind it and something about no aftermarket flywheels that will work. What I can't find is any information on my specific truck. Everyone's "long crank" comments are dealing with the 4l80 trans. But, I'm not sure if all of the engine in 99 had long cranks, since mine is a manual. So, a few questions that I cannot find the answers to:
1. Have any of you built a swap engine from this era of truck? if so, mated it to a 6 speed? if so, what steps do I need to take?
2. if mine does have the long crank and it won't work as is, can I purchase a short crank for it or is the difference in the casting of the block?
3. anything else I should keep my eye on?
overall, just wondering if I should sell the truck before I do an entire engine rebuild with it.
NCM Grand Opening Veteran
Joined: Sep 2005
Posts: 20,979
Likes: 384
From: South of giving a damn
St. Jude Donor '11, '17
I don't know about the crank but that engine is notorious for bad gas mileage. Nothing about that engine screams high performance, it was meant to make torque for pulling stuff in the truck. If it were me I'd be looking for an aluminum LS block. That truck should be an easy sell as a work truck.
Thread Starter
Racer
Joined: Oct 2005
Posts: 426
Likes: 72
From: B-town Idaho
I don't know about the crank but that engine is notorious for bad gas mileage. Nothing about that engine screams high performance, it was meant to make torque for pulling stuff in the truck. If it were me I'd be looking for an aluminum LS block. That truck should be an easy sell as a work truck.
NCM Grand Opening Veteran
Joined: Sep 2005
Posts: 20,979
Likes: 384
From: South of giving a damn
St. Jude Donor '11, '17
Found this:
https://www.onallcylinders.com/2018/...e-performance/
Nothing was said about crank length issues, etc.
Look, you can use that engine but according to the article you may need to replace most of the bolt-ons. Biggest issue I would have with that engine is the cast iron block, but the extra weight might not matter to you. My thoughts would be if I were replacing most of the other parts on the engine to just look a little longer for a LS engine. It is a great block for boost though. You may have look as far as SLC to find a more reasonably priced engine, but you do have that truck to haul it home in.
As far as I know the blocks are all the same, have you considered dropping in a Eagle kit? All the rotating assembly in one kit, forged too. 400+ ci.
https://www.onallcylinders.com/2018/...e-performance/
Nothing was said about crank length issues, etc.
Look, you can use that engine but according to the article you may need to replace most of the bolt-ons. Biggest issue I would have with that engine is the cast iron block, but the extra weight might not matter to you. My thoughts would be if I were replacing most of the other parts on the engine to just look a little longer for a LS engine. It is a great block for boost though. You may have look as far as SLC to find a more reasonably priced engine, but you do have that truck to haul it home in.
As far as I know the blocks are all the same, have you considered dropping in a Eagle kit? All the rotating assembly in one kit, forged too. 400+ ci.
Burning Brakes
Joined: Jun 2019
Posts: 1,212
Likes: 939
From: Georgetown, Tx
I don’t have an answer to your question about the crankshaft, but perhaps a suggestion to find the information.
I’ve gone through several engine builds over the years, and when I’m really stumped; what fits and what does not, I head over to a good local machine shop. These guys will have an answer to your question. They will know what fits your block and where to source the crankshaft you need, if available.
I think your LQ4 is just fine. You bought it for a budget build and there is a way to get you there. Cast iron vs Aluminum blocks are an interesting subject. They both have advantages and they both have disadvantages. Your cast iron block is more tolerant to excessive overheating whereby an overheated aluminum block may crack. I’m just saying that having a cast block is not necessarily a bad thing.
LQ4 engines came with cast iron or aluminum heads depending on the production year. If yours are cast iron, perhaps it would be best to consider the lighter aluminum heads. They should be plentiful and inexpensive.
Check out the videos listed below. Google them. They may give you a new perspective on the LQ4.
Tear-Down and Re-Build Of An LQ4 6.0L On A Bare-Bones Budget - Horsepower S12, E21
Building A Chevy Stroker From Scratch With An LQ4 Iron Block – Engine Power S1, E9
I’ve gone through several engine builds over the years, and when I’m really stumped; what fits and what does not, I head over to a good local machine shop. These guys will have an answer to your question. They will know what fits your block and where to source the crankshaft you need, if available.
I think your LQ4 is just fine. You bought it for a budget build and there is a way to get you there. Cast iron vs Aluminum blocks are an interesting subject. They both have advantages and they both have disadvantages. Your cast iron block is more tolerant to excessive overheating whereby an overheated aluminum block may crack. I’m just saying that having a cast block is not necessarily a bad thing.
LQ4 engines came with cast iron or aluminum heads depending on the production year. If yours are cast iron, perhaps it would be best to consider the lighter aluminum heads. They should be plentiful and inexpensive.
Check out the videos listed below. Google them. They may give you a new perspective on the LQ4.
Tear-Down and Re-Build Of An LQ4 6.0L On A Bare-Bones Budget - Horsepower S12, E21
Building A Chevy Stroker From Scratch With An LQ4 Iron Block – Engine Power S1, E9
Last edited by 76-Vetteman; Jun 7, 2021 at 07:10 PM. Reason: typo
Melting Slicks
Joined: Jul 2019
Posts: 2,294
Likes: 2,015
From: MA/NH Seacoast
I don't know about the crank but that engine is notorious for bad gas mileage. Nothing about that engine screams high performance, it was meant to make torque for pulling stuff in the truck. If it were me I'd be looking for an aluminum LS block. That truck should be an easy sell as a work truck.
lol, boy that's an awful take. Theres a reason the LQ4/LQ9 engines are getting stuffed into anything and everything.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
I believe the LT1 T56 will install behind the long crank LQ4, but I'm not sure there are any flywheels that would work. You'd have to use that LT1 pull-off clutch too if you found a flywheel that would work.
I also believe the cast iron head LQ4's had the long crank. If you have Al heads you might be OK.
It's likely no worth swapping the crank. Easier to find another engine.
I also believe the cast iron head LQ4's had the long crank. If you have Al heads you might be OK.
It's likely no worth swapping the crank. Easier to find another engine.
Racer
Joined: Mar 2021
Posts: 278
Likes: 43
From: Kansas
Found this:
https://www.onallcylinders.com/2018/...e-performance/
Nothing was said about crank length issues, etc.
Look, you can use that engine but according to the article you may need to replace most of the bolt-ons. Biggest issue I would have with that engine is the cast iron block, but the extra weight might not matter to you. My thoughts would be if I were replacing most of the other parts on the engine to just look a little longer for a LS engine. It is a great block for boost though. You may have look as far as SLC to find a more reasonably priced engine, but you do have that truck to haul it home in.
As far as I know the blocks are all the same, have you considered dropping in a Eagle kit? All the rotating assembly in one kit, forged too. 400+ ci.
https://www.onallcylinders.com/2018/...e-performance/
Nothing was said about crank length issues, etc.
Look, you can use that engine but according to the article you may need to replace most of the bolt-ons. Biggest issue I would have with that engine is the cast iron block, but the extra weight might not matter to you. My thoughts would be if I were replacing most of the other parts on the engine to just look a little longer for a LS engine. It is a great block for boost though. You may have look as far as SLC to find a more reasonably priced engine, but you do have that truck to haul it home in.
As far as I know the blocks are all the same, have you considered dropping in a Eagle kit? All the rotating assembly in one kit, forged too. 400+ ci.
He has a heavier engine in his vehicle currently unless he has already swapped to aluminum heads. A iron block LS is not a big deal and arguably a stronger bottom end when modified.
Before dropping it in, replace the cam, get a good set of heads and a intake set up for a light vehicle than a 6000 lb truck. It will run circles around the engine he currently has
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Melting Slicks
Joined: Jul 2019
Posts: 2,294
Likes: 2,015
From: MA/NH Seacoast
He has a heavier engine in his vehicle currently unless he has already swapped to aluminum heads. A iron block LS is not a big deal and arguably a stronger bottom end when modified.
Before dropping it in, replace the cam, get a good set of heads and a intake set up for a light vehicle than a 6000 lb truck. It will run circles around the engine he currently has
Before dropping it in, replace the cam, get a good set of heads and a intake set up for a light vehicle than a 6000 lb truck. It will run circles around the engine he currently has
Last edited by Tranz Zam; Jun 7, 2021 at 04:31 PM.
Thread Starter
Racer
Joined: Oct 2005
Posts: 426
Likes: 72
From: B-town Idaho
I believe the LT1 T56 will install behind the long crank LQ4, but I'm not sure there are any flywheels that would work. You'd have to use that LT1 pull-off clutch too if you found a flywheel that would work.
I also believe the cast iron head LQ4's had the long crank. If you have Al heads you might be OK.
It's likely no worth swapping the crank. Easier to find another engine.
I also believe the cast iron head LQ4's had the long crank. If you have Al heads you might be OK.
It's likely no worth swapping the crank. Easier to find another engine.
Thanks for the input! Do you think its not worth it because of cost?
Thread Starter
Racer
Joined: Oct 2005
Posts: 426
Likes: 72
From: B-town Idaho
Plus, I am wanting a 6 speed to drive cross country with. I appreciate your suggestion above, I'm now researching LT1 t56 options.
Thread Starter
Racer
Joined: Oct 2005
Posts: 426
Likes: 72
From: B-town Idaho
He has a heavier engine in his vehicle currently unless he has already swapped to aluminum heads. A iron block LS is not a big deal and arguably a stronger bottom end when modified.
Before dropping it in, replace the cam, get a good set of heads and a intake set up for a light vehicle than a 6000 lb truck. It will run circles around the engine he currently has
Before dropping it in, replace the cam, get a good set of heads and a intake set up for a light vehicle than a 6000 lb truck. It will run circles around the engine he currently has
Melting Slicks
Joined: Jul 2019
Posts: 2,294
Likes: 2,015
From: MA/NH Seacoast
yeah, I agree. my 75 L48 is the weakest year for engines. any LS version, iron or aluminum, would destroy what I currently have. 312 rwhp on bone stock sounds really great actually! I just need to figure out if I can stuff a short crank in this block or if I need to get a 01+ LQ4. And I'm planning on a different cam setup at the very least so I'm hoping that it will get rid of the dump-truck feel a litter.
Plus, I am wanting a 6 speed to drive cross country with. I appreciate your suggestion above, I'm now researching LT1 t56 options.
Plus, I am wanting a 6 speed to drive cross country with. I appreciate your suggestion above, I'm now researching LT1 t56 options.
I will say, a decent cam, and a set of longtubes really wake an LS up. I built a little 5.3 with a healthy cam and a good converter, and you wouldn't believe the power it makes.
Thread Starter
Racer
Joined: Oct 2005
Posts: 426
Likes: 72
From: B-town Idaho
I'm sorry I can't help you with the crank situation. I've never messed with the 99-00 engines.
I will say, a decent cam, and a set of longtubes really wake an LS up. I built a little 5.3 with a healthy cam and a good converter, and you wouldn't believe the power it makes.
I will say, a decent cam, and a set of longtubes really wake an LS up. I built a little 5.3 with a healthy cam and a good converter, and you wouldn't believe the power it makes.
what crank and what did you put it in?
Race Director
Joined: Jul 2015
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From: SW Florida.
NCM Grand Opening Veteran
Joined: Sep 2005
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From: South of giving a damn
St. Jude Donor '11, '17
Safety Car
Joined: Nov 2008
Posts: 3,717
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From: Seattle Washington
If you do go with the LQ4, be sure to replace the knock sensors. Its one of the few gremlins of this engine. After all its the only thing I have had to do so far in 19 years of ownership and 176k of miles on my 02 2500.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
Yes, unless you were planning on upgrading the bottom end anyways since you have to balance it. If keeping it stock, it should be cheaper to find another engine. You can easily go down the path of trying to make a cheap engine work and have way more in it once done compared to tracking down another engine.
Melting Slicks
Joined: Jul 2019
Posts: 2,294
Likes: 2,015
From: MA/NH Seacoast
I used a Trick Flow 228/230 .585 .585 112LSA cam with Pac valve springs, a set of 1 7/8 primary 3" collector headers, and a 3200rpm stalled converter. I'm currently still running the stock truck fuel injectors, but they seem to be keeping up fine.
It pulls like a freight train. For an alleged "work truck" engine, it does pretty well. It'll knock down 16-18mpg on the highway without overdrive too.
It pulls like a freight train. For an alleged "work truck" engine, it does pretty well. It'll knock down 16-18mpg on the highway without overdrive too.
Last edited by Tranz Zam; Jun 8, 2021 at 01:04 PM.
Melting Slicks
Joined: Sep 2010
Posts: 3,306
Likes: 697
A car buddy of mine has a 6.0 iron block 2005? in a 72 Nova. He put L92 heads on it with a 225I/230E cam and made 420 hp on the chassis dyno. TKO 600. On the Power Tour he easily got over 20 mpg.
I wouldn't mess with a 1999 block. There are thousands of newer 6.0 blocks out there for a starting points.
I wouldn't mess with a 1999 block. There are thousands of newer 6.0 blocks out there for a starting points.