My First LS Swap

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mrnapolean1

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'87
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R10
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Well looks like I am fixing to put my 1987 Chevrolet R10 pickup under the knife.
I have been doing some research on this and I have heard positive things about it.

Right now it currently has a 4.3 V6 with a nearly dead TH400 Transmission behind it.

I am going to a 5.3 V8 with a 4L60E Transmission.

I am going to have tons of questions to ask in the future.
 

foamypirate

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El Camino, baby!
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5.3L/4L60E
Well looks like I am fixing to put my 1987 Chevrolet R10 pickup under the knife.
I have been doing some research on this and I have heard positive things about it.

Right now it currently has a 4.3 V6 with a nearly dead TH400 Transmission behind it.

I am going to a 5.3 V8 with a 4L60E Transmission.

I am going to have tons of questions to ask in the future.

Ask away, good sir! Just finished my 6.0L/4L80E swap a few months ago.
 

mrnapolean1

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4.3 V6
Ask away, good sir! Just finished my 6.0L/4L80E swap a few months ago.

Some questions right out of the gate:
1. Did you get to reuse your driveshaft or did you have to shorten/lengthen it?
2. I see mounts for the engine but not the transmission. What did you use? and where you able to use the crossmember from the old transmission?
3. And what solution did you come up with for the speedometer?
 

foamypirate

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5.3L/4L60E
Some questions right out of the gate:
1. Did you get to reuse your driveshaft or did you have to shorten/lengthen it?
2. I see mounts for the engine but not the transmission. What did you use? and where you able to use the crossmember from the old transmission?
3. And what solution did you come up with for the speedometer?

1. I had a custom driveshaft built. The mounts I used (Tejas Steelworks), move the engine forward a bit, so you need a longer driveshaft. What you get for that is the ability to run the factory LS truck A/C compressor, tucked inside the frame a bit. A minor notch in the frame for hose clearance, and you're in business. You should really be building a new driveshaft anyway, preferably aluminum in 4 or 5" diameter. You are easily doubling the power of the vehicle, and increasing it's top speed significantly. The length, will of course, depend on where the mounts you choose, end up putting your engine. Once it's installed, pick a company to do the driveshaft work, and call them up. Each company is a bit different as far as where and how they want you to measure for the modifications.

2. The 4L60E mount should still be a single stud mount, like your factory transmission. If not, a factory TH350 or TH400 mount should work just fine. Factory trans crossmember will work, but typically needs to be moved forward or backward, depending on engine/trans configuration. Just drill new holes and bolt it in, wherever it lands, once the engine is in place. I had one custom built in my case, for additional exhaust clearance (double hump cross member).

3. 1990-1991 squarebody Suburbans/Blazers had electronic speedometers. Drops right in like a factory cluster. You WILL need to repin the dash connector, and add the wire for the speedometer.



Here is a pic of my crossmember:
You must be registered for see images attach
 
Last edited:

mrnapolean1

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R10
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4.3 V6
1. I had a custom driveshaft built. The mounts I used (Tejas Steelworks), move the engine forward a bit, so you need a longer driveshaft. What you get for that is the ability to run the factory LS truck A/C compressor, tucked inside the frame a bit. A minor notch in the frame for hose clearance, and you're in business. You should really be building a new driveshaft anyway, preferably aluminum in 4 or 5" diameter. You are easily doubling the power of the vehicle, and increasing it's top speed significantly. The length, will of course, depend on where the mounts you choose, end up putting your engine. Once it's installed, pick a company to do the driveshaft work, and call them up. Each company is a bit different as far as where and how they want you to measure for the modifications.

2. The 4L60E mount should still be a single stud mount, like your factory transmission. If not, a factory TH350 or TH400 mount should work just fine. Factory trans crossmember will work, but typically needs to be moved forward or backward, depending on engine/trans configuration. Just drill new holes and bolt it in, wherever it lands, once the engine is in place. I had one custom built in my case, for additional exhaust clearance (double hump cross member).

3. 1990-1991 squarebody Suburbans/Blazers had electronic speedometers. Drops right in like a factory cluster. You WILL need to repin the dash connector, and add the wire for the speedometer.


Here is a pic of my crossmember:
You must be registered for see images attach

Perfect. Now time to start locating parts now. You have been very helpful.
I am sure to have more questions in the future.
 

Old77

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I tell ya....it's good we keep @foamypirate around. :D
 

mrnapolean1

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Got another question. My truck doesn't have AC at all and in a few years I want to install Vintage air. What do I need to do in order for the vintage airs A/C compressor to mount correctly on the LS engine?

Also what preparations do I need to do now to make this happen?
 

foamypirate

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El Camino, baby!
Engine Size
5.3L/4L60E
Got another question. My truck doesn't have AC at all and in a few years I want to install Vintage air. What do I need to do in order for the vintage airs A/C compressor to mount correctly on the LS engine?

Also what preparations do I need to do now to make this happen?

There are a bunch of different brackets available. Vintage Air uses Sanden compressors, so you would just need to find out which compressor their kit uses, and get the appropriate bracket. Vintage Air themselves may offer a bracket. Holley offers one, Kwik Performance, Dirty Dingo, etc, all offer them.
 

mrnapolean1

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There are a bunch of different brackets available. Vintage Air uses Sanden compressors, so you would just need to find out which compressor their kit uses, and get the appropriate bracket. Vintage Air themselves may offer a bracket. Holley offers one, Kwik Performance, Dirty Dingo, etc, all offer them.

When I get ready to do the A/C install, Ill let them know what setup I am going to be running. :)
 

Qwk

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C10
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5.7/T56
Got another question. My truck doesn't have AC at all and in a few years I want to install Vintage air. What do I need to do in order for the vintage airs A/C compressor to mount correctly on the LS engine?

Also what preparations do I need to do now to make this happen?



Call the tech line at Vintage and tell them what you have and they will get you the correct hook ups. I had a New R4 compressor, so they just sold me the correct fittings to use for it.

Take a look at my build thread as I have some pics in there.
 

mrnapolean1

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'87
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R10
Engine Size
4.3 V6
Call the tech line at Vintage and tell them what you have and they will get you the correct hook ups. I had a New R4 compressor, so they just sold me the correct fittings to use for it.

Take a look at my build thread as I have some pics in there.

Thanks for the advice!
The A/C install is a few years away still but I want to prepare in the meantime.
 

dougbert

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With the 87 model year, you can reuse the existing fuel tank, but need to upgrade the fuel pump in the tank.

I covered what I had to do for my 1984 GMC upgrade in my thread in totally replacing the tank. Follow the GMC 1984 link in my signature. You might have to search the pages though for it.

dougbert
 

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