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Engine SwapEverything about swapping an engine into your Third Gen.....be it V6, V8, LTX/LSX, crate engine, etc. Pictures, questions, answers, and work logs.
Before I begin, I must say that this is by no means an easy swap that anyone should just jump into. Make sure you read every bit of information you can regarding the swap before you decide whether or not you’re going to do the swap. My goal of this thread is to give those interested (like I was) all the necessary information the need in one thread. Yes, I know there are LS1 swap threads, but the swaps are not identical and can be confusing to be certain what you need.
An overall picture
I currently have a 1982 Pontiac Firebird with a 1986 2.8L fuel injected engine. It has a 1985 700r4 transmission with a cable driven speedometer (The car was frankenstiened together before I bought it). I have already mechanically rebuilt the car with my dad and this last year got rid of the yellow garage paint job I bought it with.
I will add pictures of what I have done to the car later on.
I will be using a 5.3 Vortec from a 1999-2007 sierra/Silverado. It will not be modified during its initial install, as my target is to get it running properly and healthy before modding it. The engine is cable driven and thus there is no modification needed for the gas pedal. It will be mated to a 4L60e transmission again coming from a truck. The transmission must be from a 2wd truck, otherwise the tail shaft will have to be changed and the transfer case removed. Following the transmission will be a stock fourth generation aluminum driveshaft as it mounts the same as the third generation’s, however it ways about half and can be picked up for $150. The rear end will be down the road; however, it will be a posi-traction differential out of a fourth-generation f-body (I hate my open differential with drum rear brakes).
For now, I am doing a write up on what is needed to do the swap, with a general estimate of cost. I will be starting the swap later in the year when the car is off the road. I will be adding to this thread throughout my build process to try to give a more visual step by step process to swapping this engine in.
Last edited by Bstark; 06-07-2018 at 02:32 PM.
Reason: mistakes
The engine being used will be a 5.3 Vortec from a truck.
Intake:
For starters, the intake must be changed to an LS1/2/6 intake to clear the hood. I will be using an LS6 intake as it flows considerably better than the LS1 intake, and there is no EGR hookup in it. Also, the intakes have no difference in price therefore the better flowing one would be in the best interest. The change in intake will require new fuel rails and injectors, as the truck injectors ill not fit properly in the LS1/2/6 intake. Most of the time when bought used, the intake will come with rails and injectors, however in the event they do not, there are adapters that can be bought to make the stock injectors work and thus only fuel rails will be needed.
The truck throttle body will mount up and be sealed with the LS6 intake and will also work with the stock truck ecm then, operating the IAC, so to save some money, this is the route I will go.
Accessory Drive:
If keeping A/C, then the K-member will have to be notched in order to accommodate for the pulley, or an aftermarket tubular k-member can be purchased (Hawks sells them for $600).
I have heard that the stock truck accessory set up without A/C will work in our cars, however the alternator apparently hits the hood and so the hood would have to be cut to make it work.
Alternatively, ICT Billet is a great source for accessory drives. They make kits that will suit literally any combination desired. For my build I plan on using their LS Truck accessory drive that mounts the alternator on the passenger’s side (like a regular third gen) and uses an LS1 water pump from a 1999 - 2001 Camaro. The kit costs about 190, and includes the brackets to mount everything, what is still needed are the accessories themselves, luckily most 4.8/5.3’s you find will have accessories on them. The link to the accessory drive is below.
With the ICT billet accessory drive kit, you can utilize the stock truck power steering pump to save money. There are plenty of options in regard to which lines to run. The stock third gen lines will work some tweaking, or you can also use stock fourth gen lines with ease. For a combination of both, using the stock third gen return line will fit near perfectly, and the feed line from the fourth gens will fit with ease as well.
Option 1: Use ICT Billet Adapter Plates on the engine side of the mounts. Then, use stock SBC (305, 350) engine side clamshells with factory SBC mounts on the frame side.
Option 2: The motor mounts from the 4.8/5.3 do not work with the stock third-gen k-member. Spohn mounts allow for the use of stock truck clamshells and mounts the engine in the same place as factory. They are “1” setback mounts”, which means that they allow for the engine to sit in the same place the stock 2.8/5.0’s sat it, allowing for no modification in the driveshaft.
Putting the engine in the car will be much easier through disconnecting the k-member from the body, mounting the engine to the k-member, and then dropping the car back on top of the k-member. I have heard of people being able to drop the engine in the car as you traditionally would, however this is not the method I will be using due to the simplicity of the other.
Exhaust:
The stock truck exhaust manifolds are tight in the engine bay, but they do fit. There are no existing kits for exhaust routing and so you will have to either make a y-pipe yourself or get one made to tap into the original exhaust.
Speed engineering makes a set of $300 long tube 1 7/8” headers that work well with the swap. They have good fitment with the subframe and 4L60e. It allows for very easy fabricating of a true dual exhaust, or even just a single 3”.
The oil pan from the truck engine does not work with the f-bodies. It sits about 3” lower than the fourth gen f-body one does and as a result you will scrape the ground. There are kits that can be bought that include a fourth-gen f-body oil pan, dipstick & tube, pickup and windage tray. This is the route I will be going with instead of sourcing parts individually. The kit is roughly $300.
For cooling, the stock 5.0 radiator that came in third-gens as it is more than enough to cool the engine. Upper and lower rad hoses will need to be bought to make the set-up work however. They are:
Upper rad hose: Gates 20893
Lower rad hose: Gates 21505
Also, use a tee fitting in the heater hose to run the cross over tube into.
Stock fans are ample for the set up which is nice as it saves some cash.
Transmission
4L60e vs. 700R4
The 4L60e or T56 are the most common transmissions to use with this swap. They both will connect to the engine and fit in the car well. The 4L60e is the same casting as the 700R4, however you must purchase a cross-member conversion to mount it in the car. The fitment; however, is identical. Using the 4L60e allows for the stock driveshaft to be used.
Torque arm:
The 4L60e from the truck does not have a mount for the torque arm and thus there are to routes to go about solving the problem. The first solution is to get a 6-bolt extension housing from a 4L60e off a 1998-2002 Camaro/Firebird. Otherwise, it will have to have a separate mount on the crossmember.
An aftermarket torque arm can be bought from Spohn or UMI to mount the torque arm to subframe connectors, making it independent of the transmission area.
Crossmember:
There are three commonly used options when choosing transmission crossmember to use.
Firstly, the stock 700R4 crossmember can be extended to fit the position of the 4L60e. Since there is no mount for the torque arm, it will have to mount to the transmission.
Secondly, Hawks makes a crossmember that relocates the mounting point of the transmission with the same bolt pattern to the subframe. It too does not have a torque arm mount so the torque arm will either have to mount to the transmission or a custom mount will have to be made.
Thirdly: Holley makes a crossmember that has a mount for the torque arm and good clearance for headers. However, the transmission mount is about 1” forward as it is designed to be used with their motor mounts and k-member. If someone is to use their mounts and crossmember with the factory k-member, it will have to be notched to fit the oil pan.
Shift Linkage:
Use the 700R4 linkage with the 4L60e, flipped 180 degrees. This will allow for clearance for the speed engineering headers. If the shift linkage from the 4L60e is used, then the headers will have to be cut back a bit to, an have the y-pipe bend down slightly to clear the linkage.
Speedometer:
The 4L60e has vehicle speed sensor. For those will electronic speedometers it is a direct hook up. For people with mechanical speedometers, there is a mechanical drive box that can be bought for $300 which takes the electronic pulses the transmission takes and drives a mechanical speedometer gear to allow for hook up to the original speedometer cable. I will be purchasing an aftermarket speedometer and mounting it in place of where the original speedometer went. I see this as my best option as there are poor reviews with the mechanical speedo box, and it is expensive. Instead I’ll be using a digital 200kph speedometer that is the same size as the original and will hopefully fit with the plastic over my cluster. [See the electronic speedo write up in the Various section for the install].
Manual:
To swap a T56 in from a T5 or better yet a 700R4 is an entirely different thread on its own. All I know for certain is it can be done, but with a large price tag attached.
Wiring
Ah yes, the scary part. If you do not want to attempt to do the wiring on your own, many places sell wiring harnesses that have already been converted to make it work with the car. They are a good choice, however they also run $1000+.
For those like me who want to save money, the wiring is not that hard to do. As long as you are systematic in mating the third-gen harness with the LSx harness, it is a straight forward swap. There are some great threads that cover very thoroughly how to do the wiring so that just about anyone can do it. Links to them are down below:
Now that the car is wired in, the computer will have to be reflashed to get rid of its security system to stop from start and die conditions. LT1swap.com will do a computer reflash and just about any other little thing you want to the computer so that it will work in your car, all for $75.
Fueling
Regardless of what engine you have, the third-gen fuel pumps do not have the capability to pump the 60 psi the LSx engine needs. To accommodate for this, you can add an aftermarket fuel pump to the car, or better yet use a fourth-gen fuel tank.
Fourth-gen Tank:
The fourth-gen fuel tank has the proper fuel pump and fits nearly perfectly in the third-gen spot. It also has a built-in charcoal canister, so you can get rid of the can up front and clean up the engine bay. The only downside is you will have to reroute your fuel lines at the back to make it work, which can get expensive.
Stock conversion:
To use the stock third gen fuel tank and system with the 4.8/5.3, a new fuel pump and regulator are needed. Most use a corvette regulator and a Whalbro 255 fuel pump.
Routing these into the existing fuel system is a simple addition, and allows for the use of the stock fuel gauge, and no rewiring for the fuel pump as the Racetronix kit comes with a plug and play harness for third gens.
Last edited by Bstark; 08-23-2018 at 02:16 PM.
Reason: Updating
The truck engine harness will read the raw 40ppr signal the VSS from the transmission sends out and will convert it to 4000ppm. The PCM pin to tap into for the electronic speedo is C2 21 on the red and blue PCM. Most aftermarket speedometers follow this standardized reading and thus should work. If buying a prewired kit, then there will be 3 speedometer wires that will come in the kit. When running an aftermarket speedometer, only one will be needed to use, otherwise all 3 will be used with the cable x box. All that’s then left is to hook up a battery and a ground to make the speedometer work.
Cost
This is a general cost of what the majority of the build will consist of:
Vortec Engine: $500
Oil pan kit: $300
Engine Mounts: $100
LS6 intake with throttle body, fuel rails and injectors: $600
Accessory kit: $200
4L60e trans: $300
X-member: $150
Speedometer: $100
Fourth-gen tank with sending unit: $400
Various pipe fittings: $50
P/S lines: $30
Y-pipe: $150
Upper rad hose: $30
Lower rad hose: $12
Throttle body cable: $50
Intake tube: $100
Headers: $300
Computer Reflash: $75
Total Cost: $3,375
Last edited by Bstark; 08-23-2018 at 02:17 PM.
Reason: Updating
No matter what it is, I'd recommend doing a compression check on all cylinders, just so you know what you're dealing with.
You and I are both going to be doing truck LS swaps at the same time; I'm getting all of the parts ready to do a 4.8 swap into my girlfriend's '89 Firebird.
I'll be making my own thread soon.
It has over 150000, and yeah thats the plan. Straying away from the budget a little bit and am going to do a full engine and transmission rebuild. Will probably add an extra grand but then id know for sure that the engine should last.
I just pulled my 5.3L from a U Pull yard yesterday. Hoping by fall to have the engine running. My car is an original 5 speed car so I staying manual. The guy I bought my car from bought a 5 speed from a 4th gen so I'll be using that for now. Subscribing for updates! Good luck!
Pulled the engine, transmission, and electrical from the truck! Truck has been sent to the scrap yard and now its time to start building the engine.
Engine is almost fully stripped down to its block. For a high mileage engine, I am very impressed in terms of the condition it is in. Pistons have very little scoring on their sides, camshaft looks excellent, crankshaft has little play, connecting rod bearings were in good shape, and the lifters were near perfect. Am going to putting in new lifters and push rods, cam, crankshaft and connecting rod bearings, timing set, and new lifter springs in for this build. Also am going to be re-hatching the cylinder walls for preventative measure.
Hopefully will have the block fully cleaned and painted in the coming weeks!
Got the engine completely torn apart and cleaned up. It turned out to be in great condition. Still changing most internals of engine as a precaution. Waiting on one set of piston rings for a cylinder as the kit I was sent was missing one of the piston oil rings. Once I get that, should be able to reassemble the majority of the engine.
Decided to go with a stock rebuild. Using Fel-Pro Gaskets all around, and Fel-Pro Heads. Went with sealed power crank and connecting rod bearings, as well as piston rings. Going to use melling lifters and pushrods, and timing set.
Hopefully will get some pictures of the block reassembled soon!
So what will i need to do to make my 91camaro accesorys work like lights and turn signals windshield wipers etc?
None of those run off the engine harness. They run off the body harness. that will remain the same. You will either have to make a custom engine harness to tie into the main harness (C100 where body and engine come together), or isolate the engine harness. Take some time to read the stickies at the top of the LSX swap page. Plenty to read and get acclimated to.
Don't rebuild anything if you don't have to
"I hear ya! Had more trouble with machining BS trying to use aftermarket parts than I care to admit. Wish I would have stuck to factory short blocks as well. Tired of pulling apart "built" motors when guys are making twice the power on factory original stuff and racing the whole season." https://ls1tech.com/forums/forced-in...l#post19525070
After 3 years on the stock bottom end with the rings gapped for boost, I decided to upgrade to the LJMS Wiseco piston Compstar rod combo.
My engine builder handled this and delivered an assembled short block.
Mains were set to .002" Rods .0023". Piston to bore .005". Rings .024 and .028.
Stock crank.
With no change in the tune or boost (18psi at the time) the car was 3 mph slower.
After the season ended and I had about 20 passes and 1000 street miles I peeked in the cylinders with my bore scope and noted mild scuffing.
Max boost was 24 psi for maybe 6 passes.
Out it came and disassembled.
....
With stock **** (I should have left it alone) surviving better than my semi fancy stuff, I'm a bit lost.
A few friends and I have been through the exact same. From what I could tell, it all boils down to poor assembly and/or machining. Every time I’ve let an affordable machine shop touch an engine I’ve regretted it. Most simply can’t do the same quality machine work and fitment GM can. Especially if they don’t specialize in LS or turbo engines.
Not saying others don’t do a fantastic job and have good luck building LS engines. Just that my small circle of friends and I locally haven’t found anyone that can do a decent job. There are several “reputable” machine shops here and none of us have had any luck.
Almost done school for the year. Over the winter I have gotten pretty well all the swap parts I need. Engine is rebuilt as well as transmission. Hopefully am going to be putting in the engine within the next month.
Here's a picture of the engine all rebuilt and ready to go in.
What kind of dipstick are you using? That thing is sticking up really high, like a truck stick, and if that's what you're using, it won't read properly with that 4th gen oil pan.
What kind of front accessory drive are you going to use?
im doing a 5.3 out of a tahoe . i got the chance to buy the accessary brackets alt. an power steering pump . pullys etc off of a gto . do you know if these will work . im going tuurbo after i get it running . so i need these accessarys to work with the forwartd mount exhaust also .
im doing a 5.3 out of a tahoe . i got the chance to buy the accessary brackets alt. an power steering pump . pullys etc off of a gto . do you know if these will work . im going tuurbo after i get it running . so i need these accessarys to work with the forwartd mount exhaust also .
Yes they will work. They are similar to the ctsv accessories and have the vette spacing.
That thing is sticking up really high, like a truck stick, and if that's what you're using, it won't read properly with that 4th gen oil pan.
I've often thought about that. I am not sure why that matters, but maybe I am thinking about it all wrong. MY assumption with oil level is that with these Gen III/IV engines, you don't want the oil level to be above the windage tray as it is running. They are all running similar oil pumps, so wouldn't the oil LEVEL, essentially, stay the same from one vehicle to the next, and come to the same place on the dipstick? That is, aside from the tube sticking up real high like that. I could see if you were trying to use a dipstick that is not matched to the tube, then the level indication would be incorrect to the amount in the pan.
I've often thought about that. I am not sure why that matters, but maybe I am thinking about it all wrong. MY assumption with oil level is that with these Gen III/IV engines, you don't want the oil level to be above the windage tray as it is running. They are all running similar oil pumps, so wouldn't the oil LEVEL, essentially, stay the same from one vehicle to the next, and come to the same place on the dipstick? That is, aside from the tube sticking up real high like that. I could see if you were trying to use a dipstick that is not matched to the tube, then the level indication would be incorrect to the amount in the pan.
Is my assumption wrong here?
No, I don't think you're wrong; now that you put it that way, it makes more sense... I was thinking back to some other engine swaps I've done, where the tube/ engine/ oil pan are all mixed up.
For the record, on the swap I'm doing, I'm using an F-body pan and tube, but I'm just going to cut the dipstick from the donor Tahoe because I'm cheap.
I mean. Just to be on the safe side with any pickup issues. iirc The old way to do this was place the pan on the motor with a pushrod between the pickup and pan, and level(weld/bolt) the pickup at a pushrod's distance from the floor of the pan... Surely that been outdated and replaced though
thanks im gonna be using hptuners . i wasnt sure if they have base tunes or not . i wont be buying the hp tuners till end of may begining of june . im still debating on stock cam or putting in the turbo cam while i got the engine on the stand
I had someone locally who uses HP Tuners give me a start up tune. (Mail order tune but local). If you don't have a lot of experience with tuning, I have heard many good things about Frost Tuning. They do anything from mail order tunes to full tunes.
thanks im gonna be using hptuners . i wasnt sure if they have base tunes or not . i wont be buying the hp tuners till end of may begining of june . im still debating on stock cam or putting in the turbo cam while i got the engine on the stand
Stock cam- why would you even bother?
I tried it once. Its terrible. A cam swap on 02-05 truck engines in a turbo application is worth over 100hp. In an NA application is must be worth at least 50-80hp.
The stock cam is only going to take the motor to stock hp- what 280hp? Like 240rwhp. yayyy... nty
I tried it once. Its terrible. A cam swap on 02-05 truck engines in a turbo application is worth over 100hp. In an NA application is must be worth at least 50-80hp.
The stock cam is only going to take the motor to stock hp- what 280hp? Like 240rwhp. yayyy... nty
I CHANGED PLANS IM GOING WITH THE SUMMIT LS STAGE 2 TURBO CAM . im working 2 jobs now so i got more money to invest
i got the summit stage 2 turbo cam the other day .still gotta get valve springs an pushrods an lifters before i put it together ... hoping to get hptuners end of june begging of july
Cool man. I was going to try the 216/220 @ .050 grind, .560/.560 lift
Looking to get it installed in a couple weeks and then dyno tuned.
Kinda worried its a bit small. But the car is a daily. I forgot was yours a daily? thats a big cam for a stock stall or something.
Cool man. I was going to try the 216/220 @ .050 grind, .560/.560 lift
Looking to get it installed in a couple weeks and then dyno tuned.
Kinda worried its a bit small. But the car is a daily. I forgot was yours a daily? thats a big cam for a stock stall or something.
mines not gonna be a daily driver . sum street sum drag strip an sum road course . im gonna use a 2800 stall an either a th350 or th400 trans .its the summit version of the btr stage 2 turbo cam
mines not gonna be a daily driver . sum street sum drag strip an sum road course . im gonna use a 2800 stall an either a th350 or th400 trans .its the summit version of the btr stage 2 turbo cam
Funny thing is, 2800stall is the lowest, tightest converter they can make in the most efficient 9.5" size
So technically, anybody running a 2800stall is the lowest, slowest, tightest daily driver you can build.
I think you may find 2800 far too tight for that cam. The only reason I dont go sloppy stage-2 is because of my 2800.
If you are at 3800lbs with a 3.23 gear I think 3200rpm is fine.
But if you have a 3.73 it would be okay to go 3600rpm stall.
Problem with 3.73's though is the top speed is limited on a 26" tall tire to low mph, like 130's max mph or something.
And thats without factoring in converter rpm drop, so maybe ~120mph top speed limited with 26" tire.
Actually I think if you take the engine to 7200rpm it will do a bit better. Speaking of which, that is what the cam is for, hit that top rpm peak power.
I Wasn't going to spin mine past 6200 or so.
I have an 89 (bone stock) and I wanted to swap a 4.8L in and I was gonna do all new intake, exhaust and transmission I wanna know what you would recommend for intake and exhaust pipes and maybe an idea of how much horsepower I could get for a 10k budget. I'm trying to make 500-600 with a turbo is that realistic.
Power comes from the turbo. It doesn't matter what size engine you use, if the turbo mates correctly then the power of the engine is whatever the turbo can provide.
So it doesn't matter what size engine you use. 2.0L, 4.8L, 6.0L, they all make 500 horsepower if you use a 500 horsepower turbo and turn it up to utilize the total turbo flow rate.
Another way to see this is, you are not power limited with a turbo. You can have as much power as you want. That isn't the right question to be asking.
A better question is, how much power will my engine support and for how long.
One way to answer this question is to use the engine experimentally and find out how much it takes and for how long. Then repeat the experiment and draw a conclusion.
That would be very costly though. Impractical for our purposes.
There are a few of those floating around. Perform statistical analysis of the reliability list to see how well 4.8L engines and from what year hold up and for how long under what conditions.
If you do this for a 4.8L LS truck variant produced from 02-05, you may find that there is a high reliability for this engine specimen when used up to around 750bhp, which is about 580rwhp, they seem to last 10 or more years, 50,000+ mileage seems possible when using an engine that already had 200,000 miles to begin with, for the price range of roughly $400 per engine.
I have an 89 (bone stock) and I wanted to swap a 4.8L in and I was gonna do all new intake, exhaust and transmission I wanna know what you would recommend for intake and exhaust pipes and maybe an idea of how much horsepower I could get for a 10k budget. I'm trying to make 500-600 with a turbo is that realistic.
im doing a 5.3 with a summit stage 2 turbo cam an a GT45 EBAY turbo im figuring ill be 5-550 whp on 12-14 lbs of boost . mine should be running in the fall boost should come on around 3200 rpm an that cam should be good to 7000 rpm.... ls1 tech has alot of good info on combos an real world exoperience with these engines
UPDATE:
Engine and transmission went into the car, and it started finally! Being that its open headers right now its still very loud, but sounds healthy.
ICT setback plates were very easy to install and I really like the position the engine is in.
Hawks 4L60e transmission crossmember did not even come close to being able to bolt up. Had to bend, length the slot, and cut the edges of the bracing off to make it fit.
For transmission cooling, I ended up using -6an braided lines from transmission to cooler. Coming off the transmission I used an immediate 90 degree bend and it seems to fit well at the moment (tried to use 45s but it was pushing against the tunnel).
Fuel - the racetronix hotwire kit was super easy to install into the tank. However, make sure that you cut into the grommet the supply so you do not block off a very important pin size hole (as per the instructions). When I originally went to start it, it was pulling any fuel - after dropping the tank and cutting that hole, it worked perfect).
Fuel lines - Ended up routing some new hardlines up to beside the brake booster on the frame rail. From there I used 180 degree bends and fed -6an lines between the booster and the lines for a very nice and clean fit. Used 90 degree quick disconnect to -6an adapters coming off of the lm7 intake.
Wiring - since the truck harness comes equipped with just about everything it needs to run, all I had to do was supply power to the necessary wires (fuel pump turn on, ign+, starter, etc.) through the trucks fuse block. Once I went through all the needed wires its actually a lot more straight forward then it first comes across as.
Accessory drive - I went with the ICT bracket kit (551396-3) and I am very impressed with the quality of the material. Everything fit like a glove when I went to put it in.
Gauges - I am still working on getting the tach and speedo working, but all the rest were able to route up to the factory gauges.
Hood - I am very pleased to note (and I hope you stock non-cowl firebird hood owners appreciate), the stock hood was able to close with the LM7 intake! I had to trim one spot of bracing where the throttle body just tapped the hood, but otherwise everything else fit very nicely.
06-07-2018, 02:30 PM
