LS1 swap into an early C-4

LS1 swap into an early C-4

Postby Raidmagic » December 6th, 2008, 4:56 pm

I am putting an LS1 in my 87 Corvette. For this I am using motor plates made by Speed Hound I also bought my Melrose headers from them. Trey is a great guy and helpful. I clearanced my firewall just to help with some fitting issues. The harness came from Current performance and I had a special torque converter made to mate my 700r4 to the Ls. I am using a 700r4 to save some money and I had a new TCI street fighter 700r4 handy so the hurdles of this are the torque converter, lock up and tv cable. I am using a Camaro throttle body that is being controlled by a lokar cable and a kick down kit from Bowtie overdrives.
In the following posts I'm going to do some copy and paste work from threads I have started at Digital Corvettes. I didn't take pictures of everything as I get busy working and don't think to take pictures. ... corvettes/ ... gine-specs ... p?t=141825 ... z28Em4HfGi

heres more info

I like this version myself :surprised

Image ... 36&CATID=3 ... 91&CATID=3 ... 91&CATID=3 ... roker.html ... index.html ... index.html ... p?t=105822 ... index.html ... sembly-LS2 ... Index.html

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Re: LS1 swap into an early C-4

Postby Raidmagic » December 6th, 2008, 4:58 pm

I had to remove all the engine controls from the factory 87 harness this just takes time and some basic knowledge of the harness and how to read a schmetic this one is of the harness complete as it came out of the car:

And here is the new old harness paired down:

Here is the mess of wires that came out of it.
So it's done and loomed. Hopefully I can get it put in this weekend and take one more step forward.

Here is a condensed version of all my notes. As far as the wiring goes its all done except for the OBDII port.


C6 TPI PCM ground-----------------------------B1,B10,R1,R40 LS1 PCM ground

A3 secondary cooling fan DK blue/white ---------R33 cooling fan 2 relay

A9 primary cooling fan Lt blu/blk-----------------B42 cooling fan 1 relay

D7 fuel pump realy drive green/white-----------R9 Fuel pump relay control

B3 diagnostic test terminal White/blk-------------B58 class 2 serial (unpinned from TPI ALDL to LS ALDL)

B5,B11 serial data Tan---------------------------B14 ?UART 800 bus serial? (this may not work)

B6 VATTS DK/Blue -----------------------------R30 Fuel enable

B8 PPM CCM radio DK Grn/white------------------R50 Vehicle speed output

B10 12 V Ignition feed PNK/BLK-------------------B19 ignition pos volt

C1,B17 constant 12V ORG -----------------------B20,B57 constant 12V to PCM

D11 Neutral Safety Switch ORG/BlK---------------B34 PNP switch signal

Purple wire from brake switch--------------------B33 TCC brake switch

B1 black/white SES light -------------------------R46 Malfunction Indicator Lamp

White wire that went to Tach filter-----------------R10 Tach

Save INJ1 and INJ2 from TPI and connect to Pink wires on LS harness Coil/Injector drives 1 and 2

And here sits My LSX ready to run when I get my oil sender adapter. The PCM fit nicely I plan on repining the wires some day and organize them better. I also need to either replace the cheap fuse box with something better or solder it all to a fuselink once I know its working.

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Re: LS1 swap into an early C-4

Postby grumpyvette » December 6th, 2008, 9:49 pm


heres a similar thread ... p?t=130585

BTW GENTLEMEN RAIDMAGIC has done some extensive brake upgrades and a rear differential replacement on his vette so hes one of the more skilled guys on the site


thinking of building a LS series engine like the newer vettes have?? ... 1884089844



got to think this might help(look at bottom of the page) ... to_04.html ... index.html ... index.html ... index.html ... index.html ... index.html ... _comp.html ... P0808B.pdf

Articles from air flow research

If your using a bare ls2 block and don't want to tear down your current ls motor, or don't have another LS motor here is a list of parts you might need. You can get the entire kit for LS2 or 3 or customize this list for you project from sponsors or other sources.

12570471 LS2 Valley cover 83.06
12594779 PVC tube 9.01
12600325 ls2 front cover
12602548 Coolant crossover pipe 20.24
12602540 Coolant Caps (2) 4.71 each
11588714 Coolant pipe/cap bolts (4) 2.64 each
12615666 Rear crankshaft seal housing
12574293 Gasket for above 14.86
12556127 Bolts for above housing (12)
89060436 Rear Crank seal 13.50
12573460 Oil galley rear plug w/seal 4.39
11588949 Oil plug side (2) 4.71 each
9427693 Water drain plug front (4) 2.64 each
1453658 Trans dowel (2) 2.57 each
11609289 Water Drain Plug - Hex 7.23
12589016 Cam retainer Plate
11515756 Camshaft retainer Plate bolt (4)
12570125 *LS2 knock sensors (2)
12589867 *LS1 Knock sensors (2)
12585546 *LS2 Crankshaft Sensor
12585546 *LS1 Crankshaft Senor 50.00
11515756 Crank Sensor Bolt .43
12586481 LS2 Cam Gear
12556127 Cam gear bolt
12556582 LS2 Crank Gear
12586482 LS2 Timing chain
12588670 Timing Chain Dampener 11.55
12598831 LS2 Balancer
12557840 Balancer Bolt
12595365 Valve lifter Cups (4)
12551163 Valve Lifter Cup bolts (4)
12551926 Water Pump Bolts (6) 2.64 each
ARP 134 3610 LS2 Head bolts LS2004 and newer
ARP 134 3609 LS2 Head bolts LS pre 2004
ARP 234 5608 LS main stud Kit

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Re: LS1 swap into an early C-4

Postby Raidmagic » December 22nd, 2008, 5:51 pm

I picked up my dual feed fuel rail yesterday so I got out there today and swapped it onto the motor. I was then able to set my coilpacks. As it turns out the dual feed rail interferes with the coilpacks so I made some brackets that bolted to the valvecover then the coilpack bracket bolted to them. I got my alt too so all that is done now.
ON the pass. side somehow the coilpack brackets bolted right on no problem but I have all my wiring on that side so while it's busy looking it's all clean and routed well. I still have to make a bracket to bolt the fuse box too, mount the computer, get my throttle body and work out my upper rad. hose and air intake. It's getting close.
Oh yea, the stock L-98 rad. hose with a cut in the right place works perfectly for the LS.:thumbsup:



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Re: LS1 swap into an early C-4

Postby grumpyvette » December 23rd, 2008, 7:02 pm

ID really like to see details on the clutch,or torque converter and bell housing and transmission install,, motor mounts, drive shaft mods etc,along with the shifter ETC. when you get info and details, also anything on connecting gauges, sensors etc. might be very helpful to the guys thinking of following thru with a similar swap!
more info ... index.html ... index.html ... index.html
C4 LSx Engine Swap Headers


some new ls based engine options

watch this video if your thinking about a NEW $4000 dollar range crate engine option LS 327/5.3 ltr


"I made this writeup for another site after some guys were asking me questions and I figured it might do some new swappers some good on here:

Alright, I had a handful of guys wanting more info on how to swap in an LS-series of engine on a limited budget. I do these conversions pretty much for a living and will try and help shed some light on installing one of these in about anything on the lowest budget possible. Dependability, great power output, mileage and the cool factor all can come at a very reasonable price if you are willing to work a little for it.

First off a little about the engines I will be referring to. In my world I refer to either the 4.8, 5.3, 5.7 or 6.0 engines as LS1 as they share the same platform and most parts with the actual 5.7 aluminum RPO LS1 engines. I rarely do ACTUAL LS1 swaps and here is why. The two main advantages a Camaro/ Firebird/ Corvette LS1 have over a truck 5.3 for example are that the aluminum block weighs 65lbs less and they usually make around 10 horsepower more. These two factors do not warrant the big difference in price to me. There have been dyno tests were 5.3s were swapped in place of 5.7s and with all parts the same (intake, etc) they usually made 9-10 horsepower less. This is obviously NOT a large difference. I'm not bashing a true LS1 by any means, but the 5.3s can usually be bought for 1/3 to 1/4 of the price, so I tend to use them.

That said.....

With some digging around, you can usually pickup a complete 5.3 for anywhere between $250-$550. The way I usually get them is top to bottom, with truck intake/ rails/ injectors/ coils. They usually do NOT have starters, alternators, power steering, etc. This is just the way I get them. I have bought 18 of them this way.

The next biggest expense is usually the harness, which you have different options. Either harness can be made to work, be it from a truck or a LS-car harness (Camaro, Firebird) The biggest differences are that the trucks use a different injector plug type than the cars and the truck harnesses lay out differently. I try to avoid the truck harnesses as much as possible due to the odd layout, they are harder to make look nice and they are wired a little more complexly than the car ones (more keyed power sources) Here is where you have to decide what direction you are going to go, plan on leaving the less attractive truck intake (still make good power) or switch to the car style intake/ rails/ injectors to make it look more like an actual LS1. A stock harness usually will run around $150-200 dollars and you will then have to spend 3-4 hours cutting it apart/ figuring out the wires that won't be needed for your application and removing them and finding the wires you will need to connect to make your swap run. This is not a very difficult task, but it does require some patience and a good source of info, such as:

LS1 Swap FAQs

This would be the cheaper route to go if you are somewhat confident in wiring, the other route would be to buy an aftermarket or already converted harness. I have previously reconfigured all factory harnesses for my swaps but am now going to try an ebay vendor that sells all new harnesses in the $350 dollar range. These are made with the correct length wires to place the ECM better and layout more pleasing to the eyes. It would take a lot of work to modify every wire on an older harness to make it layout as nicely as one of the custom built from scratch harnesses.

The next item to consider is what transmission you plan on running. The LS engines will work with any older GM trans with some considerations. TH350s/ 700R4s/ TH400s work by using a GM part as a flexplate spacer and bolts to place the flexplate at the proper spacing, and this part provides a place for the converter snout to engage, using the original converter. The thing to consider is the downshift/ TV cables associated need to be addressed. Companies like Bowtie overdrives, etc have pieces to make them work. Obviously the 6-speeds/ 4l60Es designed to be behind the LS-engines work easily with the proper harnesses if your budget allows.

Next would be the fuel system. The easiest way to do this would be to use an inline Walbro pump sold all over the net, usually around $120 and the corvette filter-regulator combo. There are many options here depending on yor vehicle as far as getting the fuel to the pump. You can pull your factory sending unit and find a way to mount the pump to the sender and install in tank, or maybe even an aftermarket vendor makes a sending unit for your application to do just that. Other options including welding a sump to the bottom of the tank and feeding from there. Next would be installing a fuel cell or even an aftermarket tank designed for EFI use in your application. Some even just mount the pump and pull fuel through the factory pickup. This is usually okay for lower horsepower (stock swaps) and certain pumps, as some don't like pulling fuel very much and might not last forever. After the pump, you feed the corvette filter/ regulator which then has an output that you run to the fuel rail and it also has an output for return fuel back to the tank which just needs plumbed into the top of the tank. The truck intake and fuel rails includes a regulator so you can just run a line up to it and a line back from it returning unused fuel to the tank.

The only other variable here is what accessories you need to run on your engine. Of course there are vendors out there like March, Kwik Performance etc that sell complete accessories setups that are nice, but pricey, which doesn't fit into this budget writeup. I usually am doing hotrod style swaps that often only include an alternator. These are fairly simple, I usually use GM CS-style alternators, found in TBI/ TPI style 4.3-5.0-5.7 engines. These are pretty affordable, work well and are easily replaceable in case of failure. Making mounts out of simple metal (3/16s bar stock-3/8ths round stock) doesn't take too much skill. Just mount the alternator out of everythings way in your swap and most times you can even route the belt to use the factory tensioner. I have done many this way and even some with power steering and used the factory tensioner with perfect results. None ever took more than two hours to figure out. For the non creative types the easiest way to do this is to hold a straightedge across the balancer and hold the alternator up to it in a good spot and find a way to tack a bracket in place to hold it temporarily and then build some easy brackets (I love using the round bar) to mount it, it doesnt even need to adjust if you use the factory tensioner. Of course using factory LS1 brackets/ accessories is always a possibility if they fit your application and are available for use. The thing to keep in mind is that the truck/F-body/Corvette all use different accessory spacing in regards to the distance from the pulley to the block, the trucks stick out the furthest, the F-body is in about 5/8 from that and the vette is in a little more. The total difference between all three is around an inch I believe, but it is enough to make obvious bracket issues if trying to mix and match parts.

Well if you are still with me I am going to make a few lists with pricing for a few different situations.

First would be low budget, this would include a 5.3 engine swap, leaving the truck intake and using for this example a TH400 trans that was already in the vehicle.

5.3 Engine $350
Stock truck harness $150
Add on fuse panel for harness $40
ECM $40
Conversion mounts $50
Gm Trans adapter/ bolts $50
New starter $80
GM CS alternator-junkyard $25
walbro fuel pump $120
Maf sensor - used -ebay $40
New O2 sensors $120
radiator hoses $20
Fuel lines/ fittings $100
Computer reflash $150
Exhaust work/ O2 bungs $100

Total $1435

This would be the bare minimum swap into a vehicle. For example I just did a swap like this into a 69 Chevy truck. This has no hood clearance issues for the taller intake, standard truck manifolds that came with the engine fit the chassis in this application. The trucks stock radiator worked excellent as the LS-engines run pretty cool anyhow. The truck had existing electric fans like many vehicles out there already may have.

This swap would have been for the more do-it-yourself kinda guy as it used a stock harness requiring the modifications to make it work.

Now, take that same swap and add the car intake/ rails/ injectors and use an aftermarket harness which is already done, wires in with only a few connections and looks much nicer.

Previous price $1435
LS1 intake $80
LS1 rails $50
LS1 injectors $40
aftermarket harness (ebay) $350
credit back -truck harness -$150
credit back - fuse panel -$40

Total $1765
I have a few sets of cheap stainless steel LS1 header flanges for sale, PM me!

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