Picking LS swap option for 1974 C10
Picking LS swap option for 1974 C10 
I just picked up a Truck and need to pull this old tired 350 out of it. I have an LS6 in my 66 Nova and while that car hauls *** this truck is like 1500lbs more. Im interested in getting some input on swap options. I would love to do a turbo 5.3 but I really dont have 10k to put into it. This will be a used as a DD and needs to be an automatic. I have a budget of $4000 that I can spend on the engine. I was looking at an LQ9 with cam call it a day but wanted to know if there is something else Im overlooking.
Staging Lane
Joined: Jul 2018
Posts: 76
Likes: 4
I've got an LQ9/80e/BTR Stage 2 Truck Cam in my 86 C10. I love it. With a tall gear in it (2.73) I got 18 MPG Highway/15 MPG around town, and that's without being nice to it. I put 4.88s in it now and get a little under 15 MPG around town still, but I'm sure the highway MPG has dropped. Haven't tried it yet though. As impressed as I am with the power of it I am more impressed with how well it just drives normally. It just starts/runs/drives/shifts so nicely. I'd do another one in a second.
Joe
Joe
Thank you for the reply Joe. Do you feel like the truck is sluggish at all with the weight of it or looking back would of gone with say a L92 6.2 etc? I have yet to drive the truck but I want to make sure i get it right the first time.
TECH Addict
Joined: Oct 2016
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From: PDX-OR-USA
L92 out of a escalade, 
stock its got enough power to be fun..
If your a skillful hunter you can score a complete one for about 4K with transmission..
Unfortunately they often go higher..
Love that vintage of GM SWB truck..
stock its got enough power to be fun.. If your a skillful hunter you can score a complete one for about 4K with transmission..
Unfortunately they often go higher..
Love that vintage of GM SWB truck..
Your truck's curb weights are listed in the 3400-3900 range depending on wheelbase, step side or not, etc. An 08 Yukon XL (which came with the L92) is at 5800 lbs. Road tests back in the day showed the almost 2 ton truck ran 0-60 in the high 6 second range and 1/4 mile in the 14.9-15.1 range at 94 mph. Your truck has the potential to be C5 Corvette quick with one of the 6.0L or 6.2L motors in it -- without changing the cam. Sluggish?
Maybe not sluggish I guess im comparing the truck to my LS6 swapped 66 Nova which is stupid fast for cam and ported heads. I have always owned cars so this is my first vehicle that is above 3000lbs. My truck is 3850 without my fat A$$ in it.
Your truck's curb weights are listed in the 3400-3900 range depending on wheelbase, step side or not, etc. An 08 Yukon XL (which came with the L92) is at 5800 lbs. Road tests back in the day showed the almost 2 ton truck ran 0-60 in the high 6 second range and 1/4 mile in the 14.9-15.1 range at 94 mph. Your truck has the potential to be C5 Corvette quick with one of the 6.0L or 6.2L motors in it -- without changing the cam. Sluggish?
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Verdad Gallardo Thanks for the math formula. It looks like I need approx 550whp to compare to my other car. Now question is can that be done with a 6.0 truck and still keep it in a dd form.
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Joined: Dec 2011
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I have a cammed LQ4 in my 71 Jimmy, which is a 4x4 on 33x12.5s all terrains, it probably weighs a bit more than your truck. I was doing some datalogging this weekend, and my 0-60 numbers, on normal street surfaces, were in the range of 5.0-5.2 seconds (Holley datalogs and Dragy gps). Fastest runs were at 63% TPS value, any more throttle was spinning the tires. Mine is a mild cam (223/231), CNC'd stock heads (still at 9.5:1 comp), TBSS intake, 92mm TB, long tubes. 4L65e, 4.56 gears, and a Yank PT3200. It is not sluggish 
I would guess a reasonably hopped up 6.0 would make you into a 12 second truck. I suppose you can youtube all the Roadkill Muscle truck videos to see what that one did, cammed LS6, not anything special, with a TH400 and 5.13 gears.
A nice place to start would be an LY6/4L80e combo from a Van. Toss in a cam and headers and it'd be a quick combo.
If you are wanting an 11 second or faster type ride, then, yeah, I'd find a 4.8 or 5.3, 4L80e, and turbo. But may be more of a challenge with the budget. Depends on if you want to go with the sloppy style or not. OR run a setup like mine, NA, and then graduate to a turbo later. With my compression ratio, I could slap one on easily if I wanted to (and destroy my 4L65...).
In all cases, in a classic like yours, I'd look strongly at the Holley Terminator X Maxx to control both your engine and trans. Great value, and can handle a basic turbo setup.
I would guess a reasonably hopped up 6.0 would make you into a 12 second truck. I suppose you can youtube all the Roadkill Muscle truck videos to see what that one did, cammed LS6, not anything special, with a TH400 and 5.13 gears.
A nice place to start would be an LY6/4L80e combo from a Van. Toss in a cam and headers and it'd be a quick combo.
If you are wanting an 11 second or faster type ride, then, yeah, I'd find a 4.8 or 5.3, 4L80e, and turbo. But may be more of a challenge with the budget. Depends on if you want to go with the sloppy style or not. OR run a setup like mine, NA, and then graduate to a turbo later. With my compression ratio, I could slap one on easily if I wanted to (and destroy my 4L65...).
In all cases, in a classic like yours, I'd look strongly at the Holley Terminator X Maxx to control both your engine and trans. Great value, and can handle a basic turbo setup.
Thank you sir
I have a cammed LQ4 in my 71 Jimmy, which is a 4x4 on 33x12.5s all terrains, it probably weighs a bit more than your truck. I was doing some datalogging this weekend, and my 0-60 numbers, on normal street surfaces, were in the range of 5.0-5.2 seconds (Holley datalogs and Dragy gps). Fastest runs were at 63% TPS value, any more throttle was spinning the tires. Mine is a mild cam (223/231), CNC'd stock heads (still at 9.5:1 comp), TBSS intake, 92mm TB, long tubes. 4L65e, 4.56 gears, and a Yank PT3200. It is not sluggish
I would guess a reasonably hopped up 6.0 would make you into a 12 second truck. I suppose you can youtube all the Roadkill Muscle truck videos to see what that one did, cammed LS6, not anything special, with a TH400 and 5.13 gears.
A nice place to start would be an LY6/4L80e combo from a Van. Toss in a cam and headers and it'd be a quick combo.
If you are wanting an 11 second or faster type ride, then, yeah, I'd find a 4.8 or 5.3, 4L80e, and turbo. But may be more of a challenge with the budget. Depends on if you want to go with the sloppy style or not. OR run a setup like mine, NA, and then graduate to a turbo later. With my compression ratio, I could slap one on easily if I wanted to (and destroy my 4L65...).
In all cases, in a classic like yours, I'd look strongly at the Holley Terminator X Maxx to control both your engine and trans. Great value, and can handle a basic turbo setup.
I would guess a reasonably hopped up 6.0 would make you into a 12 second truck. I suppose you can youtube all the Roadkill Muscle truck videos to see what that one did, cammed LS6, not anything special, with a TH400 and 5.13 gears.
A nice place to start would be an LY6/4L80e combo from a Van. Toss in a cam and headers and it'd be a quick combo.
If you are wanting an 11 second or faster type ride, then, yeah, I'd find a 4.8 or 5.3, 4L80e, and turbo. But may be more of a challenge with the budget. Depends on if you want to go with the sloppy style or not. OR run a setup like mine, NA, and then graduate to a turbo later. With my compression ratio, I could slap one on easily if I wanted to (and destroy my 4L65...).
In all cases, in a classic like yours, I'd look strongly at the Holley Terminator X Maxx to control both your engine and trans. Great value, and can handle a basic turbo setup.
Staging Lane
Joined: Jul 2018
Posts: 76
Likes: 4
Joe
TECH Regular
Joined: Dec 2011
Posts: 420
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You've already gotten a lot of answers on this and they all make good points. With regular rubber on my truck it will spin both rear wheels until it shifts into 4th. I've driven a few fast cars and bikes in my life, and if I had to guess I'd say it can get into the 13s in the 1/4 as it sits now. I'll need a lot more traction to go any faster than that, and probably a higher stall converter if I want a decent 60 foot time. I suppose I'll know for sure before too long. I want to run it with the 4.88s before I swap it to something more reasonable. Probably 3.73s. I don't need a drag truck. I want a DD that's fun to drive.
Joe
Joe
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Joined: Jun 2016
Posts: 22,298
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From: Central Cal.
Remember that ~400HP should get you a 13 sec street truck... That handles only marginally well.
My 71 is a handful at anything other than a straight line. Its primary use is still hauling stuff so it needs to be utilitarian d2d... Yeah I can beat up some high end cars in a straight line, but I would not consider the C10 safe doing it by any means.
Everyone wants 500+ street which makes no sense to me as a real daily. IMO the ~400 mark is easy and reliable for a daily w/o going pure ape roasting meats at every stoplight or banging 2nd and getting loose.
You have a great looking truck, just keep it real for a daily.
My 71 is a handful at anything other than a straight line. Its primary use is still hauling stuff so it needs to be utilitarian d2d... Yeah I can beat up some high end cars in a straight line, but I would not consider the C10 safe doing it by any means.
Everyone wants 500+ street which makes no sense to me as a real daily. IMO the ~400 mark is easy and reliable for a daily w/o going pure ape roasting meats at every stoplight or banging 2nd and getting loose.
You have a great looking truck, just keep it real for a daily.
TECH Regular
Joined: Dec 2011
Posts: 420
Likes: 115
Remember that ~400HP should get you a 13 sec street truck... That handles only marginally well.
My 71 is a handful at anything other than a straight line. Its primary use is still hauling stuff so it needs to be utilitarian d2d... Yeah I can beat up some high end cars in a straight line, but I would not consider the C10 safe doing it by any means.
Everyone wants 500+ street which makes no sense to me as a real daily. IMO the ~400 mark is easy and reliable for a daily w/o going pure ape roasting meats at every stoplight or banging 2nd and getting loose.
You have a great looking truck, just keep it real for a daily.
My 71 is a handful at anything other than a straight line. Its primary use is still hauling stuff so it needs to be utilitarian d2d... Yeah I can beat up some high end cars in a straight line, but I would not consider the C10 safe doing it by any means.
Everyone wants 500+ street which makes no sense to me as a real daily. IMO the ~400 mark is easy and reliable for a daily w/o going pure ape roasting meats at every stoplight or banging 2nd and getting loose.
You have a great looking truck, just keep it real for a daily.
Even in a straight line, it's not the "going" that scares me, but then I have to stop it. I've got all new hardware everywhere in my brake system, larger drums from the truck HD brake option, and a 1 ton master/booster, but with 33s, its not great.
Make sure your budget is considering everything, and not just the engine/transmission itself. Many people don't budget for a good converter, good diff, and proper axle gears. That can make a big difference on your overall experience with an automatic. Most people like at least a basic TransGo HD kit in a 4L80e, and ditching the massive stock converter will help. Matching Cam, Converter, and Gears should eliminate any sluggish feeling often associated with automatics, even with a cammed 5.3 in that truck.
