LT1 Option and Opinions...?

[Thadious]

As of recently, I've been given the option to swap the 91 4.3 Tbi (150ish HP) / TH700r4 / 7 5/8" drum rearend out of my build for a '96 LT1 (260is HP)/ 4L60-E / rear disc setup from a '96 Caprice Police car....

I know I'm looking at pulling the smog stuff (not required where I live) and reflashing the PCM to remove the antitheft stuff and will no doubt either be reworking the harness myself or picking up a plug and play one from a vendor.

Any thoughts out there, hesitation or experience otherwise?

Much appreciated,
Ted.

[youngrodder]

Originally Posted by Thadious

As of recently, I've been given the option to swap the 91 4.3 Tbi (150ish HP) / TH700r4 / 7 5/8" drum rearend out of my build for a '96 LT1 (260is HP)/ 4L60-E / rear disc setup from a '96 Caprice Police car....

I know I'm looking at pulling the smog stuff (not required where I live) and reflashing the PCM to remove the antitheft stuff and will no doubt either be reworking the harness myself or picking up a plug and play one from a vendor.

Any thoughts out there, hesitation or experience otherwise?

Much appreciated,
Ted.

I am using a 95 Vette LT1 of my project. I used Street and perforamance for a lot of the brackets and A/C and Power steering pump. They are not cheap but very good quality and tech service. I bought a new harness and had my computer flashed by Howell Engine Development. Non smog for me as well.

http://howellefi.com/customer/home.php

I heard good things about Howell them plus they are located in MI. I also had my gas tank modfied by having a fuel pump dropped inside. This was cheaper then a custom tank.

The motor has been fired and the over all process was not too bad and I was very nervous as this was my first experience messing with EFI.

I am using a 4L60E trans.

Let me know if you have any more specific questions.

Good luck

[1952ssr]

I'm going the LT1 route ('94 Z28), doing the harness myself. It has been a learning experience but, to save big bucks I was willing to try. I figured if it didn't work then I'll spend the money for plug and play. My advise is get as much of the LT1 as possible, harness, fusible link, underhood fuse box, power steering resevoir and the plugs going into the car should be under the passenger side carpet. Shbox.com has alot of needed info and schematics for a Z28/LT1 but a CC should be close to the same. I've searched the net to exhaustion, but have not found alot of help. If you need something I might be able to help just let me know. This is what my dining room table looks like.

[BlueJeep]

Just read up on the opti-spark first. Yours being a 96 may not have as many issues, but I believe this is what most people hate about the LT-1.

[Thadious]

The Opti-spark is one of the things that was my concern as well... from what I understand they finally got something right on the 96 year changes. **crosses fingers**

One of the things I'm trying to find out is what exactly are the emission systems/components that can be cut out of the loop? What I'm looking to do is to keep the engine as simple as possible while maintaining/improving fuel economy and power...

I too am looking to build the harness myself. If someone was really smart, they'd document how to set the basic harness up with a schematic and components and sell a how to .pdf . I'd buy it in a heartbeat! IMO, reworking a harness isn't impossible, but if someone documented it, then people like us could sit down and work it out on the table (much like 1952ssr) is doing... save us all alot of cash (god knows we spend enough of it) for other parts and the PCM reflash!

I'll pull up the schematics you mentioned and I think I may have found a few more diggin around.

I think one of my best routes will be to get the PCM flashed, removing the emissions stuff, then put it all back in and start some of the trimming while it's still in the car, that way I can check to make sure it still works. Once I'm happy with it all, I'll dewire and pull the drivetrain for the install into the truck.

I found that the ignition switch from a mid 70's van works perfectly in the stock hole of the AD truck (so the use of the column works perfect as well) so I'll be splicing that in as well. Should be quite the mess when I'm done!

Cheers,
Ted.

PS I'm just waiting for the call from the "PO" to go have a look at it... sigh... waiting!

PPS Not sure if this will help you out, but it may go along way (or not) http://www.lt1swap.com/lt1_pcm_pinout.htm

[63 & 64 Bowties]

Originally Posted by Thadious

If someone was really smart, they'd document how to set the basic harness up with a schematic and components and sell a how to .pdf . I'd buy it in a heartbeat!

Put me in line. I'd buy one too. I don't even know how many hours I spent online thinking there was some magic "how-to" out there. But, I haven't found much useful info anywhere.
I've got a complete donor harness, so I'm probably gonna send it out to have it reworked. Looks to be a lot cheaper than a complete new harness.
One thing I'd suggest if you're doing your own is to get a shop manual for your donor car. I got one for mine and it has all the pinout info, but I'm strictly a 1st Gen guy and it was all greek to me.

[blackdiesel]

Originally Posted by Thadious

As of recently, I've been given the option to swap the 91 4.3 Tbi (150ish HP) / TH700r4 / 7 5/8" drum rearend out of my build for a '96 LT1 (260is HP)/ 4L60-E / rear disc setup from a '96 Caprice Police car....

I know I'm looking at pulling the smog stuff (not required where I live) and reflashing the PCM to remove the antitheft stuff and will no doubt either be reworking the harness myself or picking up a plug and play one from a vendor.

Any thoughts out there, hesitation or experience otherwise?

Much appreciated,
Ted.

Do it! the hp gain will be insane, it will run so much better and the 4l60e is 10x the tranny the 700r4 is(IMO)

the smog stuff can be taken off with out any problems from the ecm. i did not have to flash my ecm in my 38, my gear ratio worked out perfectly with my tranny. i bought my wiring harness from haywire and they put a resistor in the VATS to take care of the antitheft. do it, you wont be disappointed

before i slapped it in there i would put on a new water pump and opti spark!

[Atomsplitter]

Did someone say LT1?



My friend is a GM Electrician and we redid my wiring harness on my garage floor. He took out all the unwanted wires right back to the PCM connectors and after lying it out on my motor, I retaped and loomed the harness. He also reflashed the PCM with his laptop, it only takes about 8 minutes while sitting comfortably in the drivers seat as I put the PCM connector under the dash in the cab! I did have to make up some idiot lights for the Check engine and Charge indicator. You will still need the 2 Oxygen sensors so I just used a step drill to drill a hole in my exhaust down pipes and mig welded in threaded grommets that I bought at NAPA.
The power steering reservoir sits behind the alternator and you can go to any place that makes hydraulic hoses to get some made up for a reasonable cost. I also took off the engine oil cooler fillting which allows you to use the large sized filters instead of the tiny ones. I used the plastic fuel lines from the Impala as well because it has the correct connectors from the fuel rail to the fuel filter and then to the fuel pump. Easy and cheap in my motto!
Not sure if everyone likes the air cleaner but my only other choices were to send the elbow down and that would leave my filter behind the radiator (hot air = bad!) or to cut a hole in the drivers side inner fender and make a cold air intake that opens behind the grill! By the way, that elbow's a 3" PVC pipe elbow it fits nicely in the rubber connectors for the rubber intake elbow (with the hockey puck) and the Mass Airflow Sensor.
I got my new Optispark ('95 HAS the vent tube!) and water pump form a guy called Dal Slabaugh a few years ago and they were CHEAP. He's retired now but I suggest you try looking in this link for RMS Automotive who took over his buisness....may still save you guys a few bucks on original GM/Delco parts?
http://www.camaroz28.com/forums/showthread.php?t=564314

[nomrlz]

Originally Posted by Atomsplitter

I got my new Optispark ('95 HAS the vent tube!) and water pump form a guy called Dal Slabaugh a few years ago and they were CHEAP.

Dal was the best thing to happen to the GM community. that guy was almost giving stuff away.

while the engine is out i would replace the valve springs. they were weak when new and wear out fast. i have comp 26915's in my car now. also, don't buy a cheap opti if yours goes out. there only a few brands that people have had luck with (delco being best). if you want a cam, stay away from the hot cam. it is really peaky and isn't worth a shyt unless on the highway. the heads are only good for @ .525" lift without some work also. i use bryan herter at pcmforless.com to do my tunes. some guys like pcmperformance as well. hope all this helps and hit me up if you need any help.

[1sik52]

I have a 96 Impala SS LT1 for parts in case any of you need anything

[BigBlocksRule]

I hate to be the voice of dissent, but why an LT1? They're nothing more than a Vortec engine with reverse coolant flow and a restrictive intake system (similar to the Vortec!). Those are the heads that the Vortecs were designed from. I had a couple of buddies with 2nd gen Camaros, one built an LT1 and the other a Vortec engine. Cams were within a few degrees of each other. The Vortec was running carb, the LT1 on computer. They ran three 1/4 mile races and the LT won 2, the Vortec won 1, neither won by more than 1/2 car length.
If you're going to spend the time and coin to do a complicated swap, find an LS and outrun the big block guys!
OK, let the flames begin!

[1sik52]

Originally Posted by BigBlocksRule

I hate to be the voice of dissent, but why an LT1? They're nothing more than a Vortec engine with reverse coolant flow and a restrictive intake system (similar to the Vortec!). Those are the heads that the Vortecs were designed from. I had a couple of buddies with 2nd gen Camaros, one built an LT1 and the other a Vortec engine. Cams were within a few degrees of each other. The Vortec was running carb, the LT1 on computer. They ran three 1/4 mile races and the LT won 2, the Vortec won 1, neither won by more than 1/2 car length.
If you're going to spend the time and coin to do a complicated swap, find an LS and outrun the big block guys!
OK, let the flames begin!

Amen! When I swapped from my vortec to my LS1 in my 52 it was like night and day. Everyone thinks the LS1 are sooo expensive but have actually come way down in price over the years. Now that I am building my wifes 70 Blazer I am installing a LS2 which runs circles around the LS1

[nomrlz]

Originally Posted by BigBlocksRule

I hate to be the voice of dissent, but why an LT1? They're nothing more than a Vortec engine with reverse coolant flow and a restrictive intake system (similar to the Vortec!). Those are the heads that the Vortecs were designed from.

this is true. the iron LT1 heads and vortecs are identical. they both flow @ 225cfm and outflow stock alum LT1 heads. the one nice thing about an LT1 is any newer SBC parts work like crank, rods, roller rockers, valve covers. makes it easy to get deals on parts. my 160,000 mile LT1 in my 4700lb wagon has no problem hangin with mild big blocks either. the LS motors are definitely a better engine but if you have an LT1 available, it won't disappoint

[youngrodder]

Originally Posted by BigBlocksRule

I hate to be the voice of dissent, but why an LT1? They're nothing more than a Vortec engine with reverse coolant flow and a restrictive intake system (similar to the Vortec!). Those are the heads that the Vortecs were designed from. I had a couple of buddies with 2nd gen Camaros, one built an LT1 and the other a Vortec engine. Cams were within a few degrees of each other. The Vortec was running carb, the LT1 on computer. They ran three 1/4 mile races and the LT won 2, the Vortec won 1, neither won by more than 1/2 car length.
If you're going to spend the time and coin to do a complicated swap, find an LS and outrun the big block guys!
OK, let the flames begin!

Yes, LS motors are great but close to twice as expensive. If money was not an option drop in an LS7 and run away from everyone..right? For the reliability and fuel economy you can't really go wrong with any EFI power plant that a person chooses.

[1sik52]

Originally Posted by youngrodder

Yes, LS motors are great but close to twice as expensive. If money was not an option drop in an LS7 and run away from everyone..right? For the reliability and fuel economy you can't really go wrong with any EFI power plant that a person chooses.

LS1 arent that expensive anymore. One can be had for about $1,000-$1200 now days. And by the time you do the mods to the LT1 to get the horsepower up to what a LS motor is you will end up having the same amount of money in it. Im not knocking the LT engines, just stating my experiences.

[youngrodder]

Originally Posted by 1sik52

LS1 arent that expensive anymore. One can be had for about $1,000-$1200 now days. And by the time you do the mods to the LT1 to get the horsepower up to what a LS motor is you will end up having the same amount of money in it. Im not knocking the LT engines, just stating my experiences.

I agree with you. I am dating my project some. When I was looking for the engine, that was the case, but they have come down. I am not doing any mods. I always feel it take away from some of the dependability. It might just be me though

The funny thing was I came across a ZR1 motor at that same time but the price tag was 15,000. I said "no way that is more then my whole budget". Boy was, I wrong, I passed that sometime ago....

[nomrlz]

around here. you can get a 5.3L truck/van engine for $500 give or take. i paid $450 for one with ecm for my boys project. the 6.0L are still bringin a good grand tho. now after buyin the truck engine a LS1/4L60 out of a 98 camaro is available for $1500 OBO. so, these LS's are definitely affordable these days

[1952ssr]

There was a guy on Ebay selling a program like you guys are talking about. I pondered buying it but, didn't.
If I could do it over again I would find me a LQ8/4L80 from a truck or van and go that route. I had to please a wife that wanted a motor with at least 300HP, so I talked her down to the LT1/4L60 ($1200)from the 400HP ($3000)crate motor from year one. That motor alone was gonna be more than my truck with wheels/tires together.

[nomrlz]

Originally Posted by 1952ssr

I had to please a wife that wanted a motor with at least 300HP

i typical iron head LT1 with full bolt-ons makes 280rwhp. stock they make around 225rwhp (260hp advertised at crank). get a good convertor and it will fly. here is my 4700lb 160,000 mile stock (only spring and 1.6RR) every day driver.

[BigBlocksRule]

I'm doing a complicated build myself - a '57 body on a '63 trailing arm chassis, '85 front crossmember, '98 interior, '96 4L80E, 14-bolt semi floater from a '92 (33 spline axles are monsters!). I'm basically picking all my favorite parts from different generations of trucks. I'm gonna cheat a bit on the engine - block is an LS7 that I'll stroke to 441 with factory CNC'd LS7 heads. I'll run a carb, I think the LS engines with carbs and relocated coil packs are some sweet looking mills, much better than the injected wiring messes than need covers. I'm expecting about 650hp with a moderate cam.
I have plenty of projects, this is the one I call, "long term", hope to finish it before I croak

[nomrlz]

Originally Posted by BigBlocksRule

block is an LS7 that I'll stroke to 441 with factory CNC'd LS7 heads. I'll run a carb, I think the LS engines with carbs and relocated coil packs are some sweet looking mills, much better than the injected wiring messes than need covers. I'm expecting about 650hp with a moderate cam.

it just went from six to midnite

[BigBlocksRule]

Originally Posted by nomrlz

it just went from six to midnite

That quick, too!!!

Watch for totalled late model trucks/suburbans/tahoes with the 6.2L in it. That can be made into some kinda power monster!

[nomrlz]

Originally Posted by BigBlocksRule

That quick, too!!!

Watch for totalled late model trucks/suburbans/tahoes with the 6.2L in it. That can be made into some kinda power monster!

hot rod mag did a nice write up on putting LS3 heads ($1050) on a truck short block and a few comp cams. damn things were crankin out over 500 horses like it was nothin

[nomrlz]

those 10 bolts are damn strong too. it only took a few hundred launches pulling 1.69-1.72 sixties to blow out the stock aubrun posi. that is on top of all those street miles too. there are a few guys up your way on the impalass forum that could help you with parts too

[BigBlocksRule]

Besides, an LT1 swap today is kinda going backwards in technology...