Anyone ever installed a FI LT-1 into a 73-87 model?

[wildmanaaron]

I had a few questions about installing an LT-1 into a 1981 Blazer 2WD. The PDF file from Street & Performance is pretty helpful and is quite tailored to our Trucks.

First of I want to use the factory Camaro brackets on this install. I am pretty sure that the driver's side will mount on the factory SB mounts, but the RH side will probably not with the air compressor mounted down low on the factory brackets.

1. Does anyone know how much needs to be removed to get the compressor to keep from hitting the frame?

2. I have been told that I can use the 700R4 as long as it has a Vehicle Speed Sensor attachment. My transmission doesn’t currently have a VSS but I have heard that they can be installed easily and with the male end to attach to my cable driven speedometer. Has anyone else used the 700R4 transmission behind an LT-1?

Any other tips or suggestions would be great.

[bigarmzz]

calling ken......oh n2trux....this one's his

i "know" either he's done it, or know's someone that has

[magnethead]

i dont know about the 700...an LT1 and 6000 pound truck dont seem like a good thing, hope you have 3.73's or 3.90's or it might not like OD.

[bigblock73]

6000 pounds?? 2wd trucks/Blazers are usually 4000 pounds and under...4wd's would be slightly larger. Now a tank like yours...that may be 6000.

[piecesparts]

Why wouldn't a LT-1 work? You have the equivilent in most of the newer trucks. If your truck weighs 6000 pounds, then it must be really loaded with a sturdy bed and other stuff, my 84 GMC SWB is at 4000# Max. I am working pn putting a L-98 TPI with vortec heads in my 91 daily driver and it should increase my HP by 100%. As for the 700 R4, most LT-1 motors are tacked onto 4l60 trannies, which is a 700 in an updated design. The tranny can be changed out for a VSS setup or go with the tailpiece that S&P sells that wioll allow you to run both a mechanical speedo and a VSS for the computer. You will have to get the computer updated for this change, but it is not impossible. The LT-1 will give you around 260 to 300 HP depending on what you choose to do for injectors and the computer program. My wife's 95 Impala SS is going at 300 HP with headers, and cold air intake. I updated the injectors to a set of (remember that I said this) FORD racing injectors. Their pintle tips design is a better design than the wafer-disk units from GM and they are purchased cheaper than the GM ones. S&P sells them, also. Unless you have the LT-1 in hand, I would consider the LS-1 instead. IT is lighter and more versatile in performance options. Not to mention the serious HP it makes. I am working on an install of one in a 1968 Chevy Truck for a Streetrod project.

[Jonboy]

Check out the Jaguars that run site also, I think it's www.jtr.com . They have a lot of good TPI swap info there, and some good LT-1 info as well. I would try to score the engine and trans as a unit, to get everything to match.

[wildmanaaron]

The Blazer I have is a 2WD model. Doesnt weigh much.

Basically I know alot about the parts that I need for a generic LT-1 or possibly LS-1 swap. What I would like to know more is about the specific problems or suggestions with running one of these engines in the 73-87 models, such as clearance for using motor mounts, type of fuel lines used, etc.

[Jonboy]

I think you could use the towers you have in the truck currently, just move the passengers side back a little bit. Use an 87-up Blazer/burb tank and lines. I can't remember which side the fuel comes in on an LT-1, but those will have the lines on the passenger side of the vehicle. You may be able to clock the fuel pump and sending unit 180 degrees out to make the lines come out on the drivers side, if needed. I would think the B-body front dress and accessories would be the best bet, due to availability. It is not quite as compacted as the F and Y body stuff.

[magnethead]

I didnt see where it said blazer..i thought he was saying like into a C10 or something

for the reecord, my truck was 6680 going INTO the rock quary (and for the record, it was 8400 and change leaving)

[wildmanaaron]

Come on now. I know I have seen other 73-87 owners on here talking about LT-1 and LS-1 installations before.

[1987 Shortwide]

My caprice wagon weights 4400 lbs and it had an LT1 stock, they're fine in our trucks...

[Captkaos]

I don't have any personal experience with the LT1's, but it should drop right in since the block is the same at the previous models.

LSX motors are a completely different story though.

[Low84]

I bought an lt1 for my truck. Haven't gotten to installing it though. I need the harness and computer but they're not exactly cheap. I think I'm just going to go ahead and converted to carb, and get it over with.

[Russell]

Originally Posted by Low84

I bought an lt1 for my truck. Haven't gotten to installing it though. I need the harness and computer but they're not exactly cheap. I think I'm just going to go ahead and converted to carb, and get it over with.

Too bad those LT1s use that optispark junk -- Be really easy to slap a TPI ECM + wiring harness onto one of those engines otherwise...

[Low84]

Originally Posted by Russell

Too bad those LT1s use that optispark junk -- Be really easy to slap a TPI ECM + wiring harness onto one of those engines otherwise...

Yeah. The whole reason in me buying the engine was to go fuel injected. But after checking prices, I don't know. I can buy the conversion intake manifold and a nitrous kit and have left over cash when comparing to how much it would cost me for the Harness and Computer.

[72C203503ONTHETREE]

The TPI is injected but its mainly for low down torque, not horsepower that the LT1 and LS1 is known for. As far as I know the LT1 still uses the same motor mount locations as the previous small blocks. Swapping over to TPI shouldnt be that hard, there is still a hole where the distributor goes, theres a dummy shaft that runs the oil pump and I think a cam sensor on top so a distributor bolts right in with the proper intake that used a distributor.

[wildmanaaron]

Right the motor mount issue isn't what I was concerned with. I was wondering about the clearence for the A/C Compress on the RH side. I have seen that another member didnt have to notch anything, but I think it was an LS-1 engine.

Here's what I have to work with so far:

Fuel Tank & Fuel Pump
The LT1 requires 38 to 47 lbs of fuel pressure, therefore I will use an AC DELCO EP-241 fuel pump along with sending unit #25094539 from GM.

Cruise Control-What do I have to do to get it all working with the new engine. I have a vacuum set-up off of a 1982 Blazer that I could use.

Transmission-I have been told that I can use the 700R4 as long as it has a Vehicle Speed Sensor attachment. My transmission doesn’t currently have a VSS but I have heard that they can be installed easily and with the male end to attach to my cable driven speedometer.

Power Steering Set-up-I would like to use the Camaro factory power steering set-up as well on this conversion. Has any other owners used the LT-1 factory power steering parts on their 73-87?

Fuel Lines-I have been told to use the factory fuel injection fuel lines found on the later model Blazers. Since the didn’t make a 1983-1991 2WD Blazer, the 4x4 lines were said to fit the same as they did on the 2WD models.

[72C203503ONTHETREE]

Have you tried checking out March, they make all kinds of brackets for V8's of all kinds, not sure if they make any for a LT1 transplant yet. AS far as power steering, I think you should have the metric O-ring hose ends that the LT1 pump has, at least the newer car lines like the G bodies and F bodies had it by then. You may have to have custom lines made at a farm equipment place. There are 2 different accesory setups, one for the Vette and one for the F bodies/B bodies. Sounds like you have the VSS thing and the fuel system figured out. Have you thought about using the 4L80 trans? Its basically a turbo 400 updated and with an overdrive fourth gear. It is a lot stronger than the 700R4/4L60.

[Russell]

Originally Posted by wildmanaaron

1. Cruise Control-What do I have to do to get it all working with the new engine. I have a vacuum set-up off of a 1982 Blazer that I could use.

2. Transmission-I have been told that I can use the 700R4 as long as it has a Vehicle Speed Sensor attachment. My transmission doesn’t currently have a VSS but I have heard that they can be installed easily and with the male end to attach to my cable driven speedometer.

3. Power Steering Set-up-I would like to use the Camaro factory power steering set-up as well on this conversion. Has any other owners used the LT-1 factory power steering parts on their 73-87?

4. Fuel Lines-I have been told to use the factory fuel injection fuel lines found on the later model Blazers. Since the didn’t make a 1983-1991 2WD Blazer, the 4x4 lines were said to fit the same as they did on the 2WD models.

Hey man, couple comments here:

1. I'd use the stock LT1 cruise system -- If it is anything like the earlier TBI truck setups, it'll use a VSS signal sent out by the ECM. Far more accurate, and reliable than the old vac setups are, if you could even come up with a way to bolt one up!

2. 700r4 will be just fine. Its easy to install the required VSS into the tailshaft housing. Those inline VSS thingers may not work with an LT1 like a TBI or TPI vehicle. The LT1 uses an AC 40 pulse per driveshaft rotation signal, while TBI uses a 2000 pulse per mile, and TPI uses both a 4000 and 2000 pulse per mile signal. Doing so will cost you your speedo cable, but you can easily retrofit a stock electronic speedometer from an 89+ suburban, blazer, or crewcab pickup into your truck. They use the 4000 pulse per mile signal that the LT1 ECM outputs.

3. Everything should bolt straight up using the Camaro parts. Your 81 should have an o-ring steering box, and so long as the lines reach, it should hook up like stock.

4. You're correct, the 2wd and 4wd frame rails are identical (same part number even) and the 4wd fuel lines should bolt straight up

[Captkaos]

If you are running F-body accessories on the LT1, then the A/C will not work. It will hit the crossmember/frame. If you want factory, you need the Y-body accessory brackets. They will work on a Truck.

For the VSS and cruise, you need a speedo from a '83 up truck that has the tail on it and the VSS on the trans.

As stated in the TPI writeup, the 4x4 EFI lines will work. There is nothing different on the fuel lines for 4x4 vs 4x2.

[Captkaos]

I am wondering if you have seen this (I knew it was out there, just found it again) It will answer alot of you questions.

http://hotrodlane.cc/PDFFILES/83chevyLT1install.pdf

[Jonboy]

There is an extra boss on the right side of the block for the engine mount. The clamshell mounts upside down (opposite of the other side) and in the rearward set of holes to clear the A/C compressor. That lesson took a while to learn.

[wildmanaaron]

Thanks guys. I was hoping to get some better in-depth information, other than the regular "it will work". Fuel injection swaps are not as easy as everybody says.

I need to do some extra homework on cruise control systems, such as where they bolt in, what are the parts required, etc. I just don't have much of an understanding on the workings of the electric cruise control system.

[Jonboy]

You might try to score a factory service manual. The cruise on B body cars is a stand alone box with a cable that goes to the throttle body, and is usually mounted to the left fenderwell. Seems like it is controlled by the ECM, though. If you do swap, I would bite the bullet and get an aftermarket harness. That will simplify your swap immensely.