Anybody swapped in an LS1?

[cuda]

I'm kicking around engine options for my recently acquired '87 1/2 ton 4wd, The TBI motor that's in it, while reliable, is seriously lacking in the power department. I thought about stroking the engine, but the factory heads would have to be replaced, stroker kit, machine work, etc., and the bill starts to add up. I am also considered building the 454 that I have laying around in my garage, but that conversion also starts to add up via a new transmission, mounts, removing the a/c box, machine work, rebuild kit, etc. By the time I've invested that much money, time, and work into one of these two alternatives, I could buy a complete, turnkey 5.3/4L60E or 6.0 vortec/4L80E (best trans I ever had) with computer, harness re-wired etc. for ~$2500-3000. However, I don't know if anyone makes motor mount kits and various other adapters that would be necessary.

If anyone knows anything about this swap for this generation of truck, I would be most grateful for any info. I put an LT1/T56 in my '69 camaro, so I understand most of the hidden costs that add up, particularly with port injection swaps, but I want to break this down to see if it would be only marginally more expensive than the two aforementioned options. If it is, I would rather have the clean power and reliability of the new combo. Any thoughts are welcome. Thanks.

[78chev]

I have been thinking about the same thing in my 78. I put on A LOT of miles. I have done the math and as far as the power vs. cost goes the LS1 is more expensive, but, if you drive a lot the LS1 quickly makes up for it. Plus if you live in a smog check state (I live in CA) the LS1 will always pass!

[BaddBusa2005]

the ls1 swap is not much more if any than a big block swap or building a sbc. Also it would definately be more reliable. Sorry I am not a fan of carburation. I have an 5.3/4l60e in my truck, daily driven. It has been in the truck for about a year and a half, gets roughly 22-24mpg and runs good. I took it to the track friday and it pulled off 8.9x @ 78MPH.

[G-old]

Originally Posted by BaddBusa2005

Also it would definately be more reliable. Sorry I am not a fan of carburation.

2X, My dad has had his 82 long bed with a 5.3L since 2000 and has never given him any trouble what so ever. Mine is also a 5.3L and I will never go back to TBI, original, much less carb.

[Russell]

Engine mounting is super easy -- Spend 100 bucks on the adapter plates, or just make your own, and bolt it straight in using the factory engine mounts.

[midwestcar]

Originally Posted by Russell

Engine mounting is super easy -- Spend 100 bucks on the adapter plates, or just make your own, and bolt it straight in using the factory engine mounts.

exactly what he said!!!!! have someone go throught your wiring harness or buy aftermarket, flash computer and your done

[cuda]

Great to hear that this is not uncommon and can be done relatively easily, but does anyone have anything more specific? Who makes the adapter plates for the motor mounts? I could make some myself, but I don't have any geometry specifics and I don't have the motor/trans to use as a mock-up. If I go with a 4L60E I'll assume that the stock crossmember/trans mount can be reused as is because it already has a 700-R4. If I use a 4L80E ( I want one bad ), what are my crossmember options? TH400 mount? For some reason, I don't think they're the same. What fuel pumps are people using? I have dual tanks, so this might hurt a bit. Thanks for the quick responses, fellas. Anything else?

[wildmanaaron]

Check out this link for a similiar install:
http://www.hotrodlane.cc/77chevytruck/77chevy.htm

Go to LS1tech and check out the conversion forums for a lot more information that you will need. One minor problem is the speedometer. The 73-87 Trucks had a mechanical speedometer in them and the LS-1 uses an electronic speedometer. You can either use an aftermarket speedo or convert the tailshaft to accept a mechanical "cable driven" speedometer for around $475 more.

I am getting ready to start on my conversion within a month.

[BaddBusa2005]

Originally Posted by wildmanaaron

Check out this link for a similiar install:
http://www.hotrodlane.cc/77chevytruck/77chevy.htm

Go to LS1tech and check out the conversion forums for a lot more information that you will need. One minor problem is the speedometer. The 73-87 Trucks had a mechanical speedometer in them and the LS-1 uses an electronic speedometer. You can either use an aftermarket speedo or convert the tailshaft to accept a mechanical "cable driven" speedometer for around $475 more.

I am getting ready to start on my conversion within a month.

that is a good read for sure. I used the street and performance mounts as well.

[KMK454]

Get an LS2 from a totaled C6 or 05+ GTO... 400hp/400tq.

I have 52k miles on my 05 'vette with an LS2, never had a single drivetrain related issue and the motor feels stronger than ever. In fact, it's just getting broken in. Seriously, great motors, and I can only imagine how awesome one would be in a truck with the T56 6-speed!!

[Jim85IROC]

Originally Posted by wildmanaaron

Check out this link for a similiar install:
http://www.hotrodlane.cc/77chevytruck/77chevy.htm

You'd think that a company that used to specialize in thirdgen f-body performance would know that the LS1 didn't come out of an IROC

[BaddBusa2005]

Originally Posted by Jim85IROC

You'd think that a company that used to specialize in thirdgen f-body performance would know that the LS1 didn't come out of an IROC

lol

[Russell]

I bought my mounts from a parts house company called Mopac, they were 75 bucks after tax, and obviously came from someone's garage Far from beautiful like S&Ps shiny ball beveled things, but they get the job done, and look factory after being installed.

Wiring is also a super easy thing to do, just use the factory harness, and you only need to change one pin from one location to another, then add splice in several wires from your factory harness.

Programming involves removing VATS, and any emissions systems you are not installing. www.pcmamerica.com has the best price I've seen out of a programmer to date.

As far as gauges go, you can buy / build adapters for both the factory 73-87 sending units, and you can install an electronic speedometer from a 90-91 Crewcab, Suburban, Blazer, or Jimmy, as they use the same 40 tooth reluctor ring sensor in their transmissions as the 4l80e, and 4l60es do, just splice the factory DRAC + speedo in along with the PCM, they are just fine sharing the signal from the VSS.

I'd personally use the newer truck's aluminum radiator + overflow bottle to avoid issues with steam lines, and rad hose exits etc. Both them, and the factory fuse block can be mounted in these trucks as if they came that way from the factory.

[wildmanaaron]

Originally Posted by Russell

just splice the factory DRAC + speedo in along with the PCM, they are just fine sharing the signal from the VSS.

Russell,

I had talked to before about the electronic speedometer and have had a hard time finding a 90-91 electronic cluster to get the wiring off of. When I got my clusted out of the junkyard, I didn't get any of the wiring, except for the dash cluster pigtail. What does the DRAC look like and how much of the wiring do I need. Pics would be greatly appreciated if possible.

[cuda]

Thanks for all the help. All have been very helpful thus far on this forum. Glad to be here.

[BaddBusa2005]

i have the 1991 burban guage cluster in my truck, works nicely

[cuda]

Where did you guys get your Suburban/Blazer electronic speedos/instrument clusters? Sounds like they wouldn't be too common given that they were only made for two years. There don't seem to be any in the boneyards in my neck of the woods. However, it is good news that this alternative to aftermarket speedos/tailshafts exists. Several hundred dollars for a tailshaft just to use a gear driven speedo never made any sense to me. I would go without one for a very long time.

[BaddBusa2005]

picked two up on ebay for 25 bux a piece, i like the stock look of it.

[cuda]

Aahhh, ebay. Occasionally I miss the obvious.

[Russell]

Yeah, for being a two year only item, they seem to go cheap, and are frequently found...

[Russell]

The DRAC is just a little yellow or clear module back behind the dash somewhere that converts the signal your transmission makes to what your speedometer can use.

You'd basically need the two wires that run from the transmission's speed sensor to the DRAC, likely along with a power and ground wire, then run the 4000 ppm output to the speedometer, which would also need a power and ground wire.

The DRAC probally has another output for the electronic cruise control setup, but you won't need it, unless you are retrofitting cruise in as well.

The PCM would need to be hooked up to the two wires that run to the speed sensor as well, its fine to splice them all together, as neither the DRAC, nor the PCM should be changing the voltage the sensor produces at varying speeds.

I don't have a DRAC on hand to take a picture of, but if you pop over to www.fullsizechevy.com, and search for DRAC, you'll find gobs of pics, and probally wiring diagrams / pinouts as well.

[Roper]

Originally Posted by Russell

The DRAC is just a little yellow or clear module back behind the dash somewhere that converts the signal your transmission makes to what your speedometer can use.

You'd basically need the two wires that run from the transmission's speed sensor to the DRAC, likely along with a power and ground wire, then run the 4000 ppm output to the speedometer, which would also need a power and ground wire.

The DRAC probally has another output for the electronic cruise control setup, but you won't need it, unless you are retrofitting cruise in as well.

The PCM would need to be hooked up to the two wires that run to the speed sensor as well, its fine to splice them all together, as neither the DRAC, nor the PCM should be changing the voltage the sensor produces at varying speeds.

I don't have a DRAC on hand to take a picture of, but if you pop over to www.fullsizechevy.com, and search for DRAC, you'll find gobs of pics, and probally wiring diagrams / pinouts as well.

Why would he have to change his speedometer? On his 4 wheeldrive the mechanical speedo cable goes to his 208 transfer case. Not his transmission.

[Roper]

Originally Posted by cuda

I'm kicking around engine options for my recently acquired '87 1/2 ton 4wd, The TBI motor that's in it, while reliable, is seriously lacking in the power department. I thought about stroking the engine, but the factory heads would have to be replaced, stroker kit, machine work, etc., and the bill starts to add up. I am also considered building the 454 that I have laying around in my garage, but that conversion also starts to add up via a new transmission, mounts, removing the a/c box, machine work, rebuild kit, etc. By the time I've invested that much money, time, and work into one of these two alternatives, I could buy a complete, turnkey 5.3/4L60E or 6.0 vortec/4L80E (best trans I ever had) with computer, harness re-wired etc. for ~$2500-3000. However, I don't know if anyone makes motor mount kits and various other adapters that would be necessary.

If anyone knows anything about this swap for this generation of truck, I would be most grateful for any info. I put an LT1/T56 in my '69 camaro, so I understand most of the hidden costs that add up, particularly with port injection swaps, but I want to break this down to see if it would be only marginally more expensive than the two aforementioned options. If it is, I would rather have the clean power and reliability of the new combo. Any thoughts are welcome. Thanks.

Why not just get an older built 350that is carburated with no polution junk?
Example I put a LM1 in mine, added edelbrock performer non egr intake and an edelbrock 650 thunder series off road carb, dual exhaust, etc.
Im not sure of my horsepower but im guessing 275. But their are all kinds of crate 350s that are 300 plus and they are just a bolt in deal. Lots of bang for the buck.
Honestly though with fuel prices the way they are if I was you I would be looking at putting a diesel in it. A 6.2 with aftermarket turbo would be a easy bolt in. But a 6.4 or Cummins would be way better. I know it can be done. Im just not sure how much work and expense it woukld be.

[Russell]

Its not just for the speedometer, the speed sensor is an extremely important sensor to the PCM, without it, the engine will not run correctly without getting the chip changed, and even then, it'll have problems with stalling out under deceleration, with emissions controls, fan controls, and the highway mode function.

A cummins diesel is a fantastic engine, but they are very heavy, and are pretty tough to shoe-horn into these trucks, there is a lot of suspension work etc that needs to be done so the truck handles properly. 6.2 / 6.5L diesels are great for getting good mileage, but without spending a fair bit of money on one, they can be real slugs.

The new LSx engines, esspecially the lower displacement 4.8Ls and 5.3Ls get excellent mileage, similar to what a 6.2L gets if geared properly, and driven nicely, with way more power available if needed

[Roper]

Originally Posted by Russell

Its not just for the speedometer, the speed sensor is an extremely important sensor to the PCM, without it, the engine will not run correctly without getting the chip changed, and even then, it'll have problems with stalling out under deceleration, with emissions controls, fan controls, and the highway mode function.

A cummins diesel is a fantastic engine, but they are very heavy, and are pretty tough to shoe-horn into these trucks, there is a lot of suspension work etc that needs to be done so the truck handles properly. 6.2 / 6.5L diesels are great for getting good mileage, but without spending a fair bit of money on one, they can be real slugs.

The new LSx engines, esspecially the lower displacement 4.8Ls and 5.3Ls get excellent mileage, similar to what a 6.2L gets if geared properly, and driven nicely, with way more power available if needed

Man that electronic stuff sounds like something im happy that my truck doesnt have<grin>
Hey yesterday a friend of mine showed me his new<to him> truck. Its an 85 2 wheel drive with a 6.2. Its got a banks turbo on it. I took it for a test drive. It was way better than I thought it would be. I would guess it was about the same as a stock 350<220 hp>?.Apparently the turbo doesnt hurt the mileage on those 6.2s.
Those 6.2s seem to be cheap to buy as well. Plus no electronics. Just a direct bolt in job.
What about the 6.5 chevy diesel. How much trouble to put one of those in a pre 88 chev?