72 C20 LS Swap/Build
 

Hi,

New to this forum thing still. I have learned so much from reading other build threads and thought I would post my progress on my LS swap into my C20. I've been working on it at my dad's place where he has a great big garage full of tools.

I wanted to do the swap since the 350/350 combo (not original - PO changed it out already) I had was getting really terrible mileage and lacked power. The donor truck is a 2009 Silverado with a 4.8 and 4L60E.

My truck is used for work and for fun driving like on road trips. I'm after the better mileage, more power, ease of starting and reliability from the swap. Not really concerned with upgrading much beyond stock.

I'm on a budget as well so am inclined to fabricate and/or reuse things that will work rather than buy new. I'll try to use part numbers, sources and cost in Canadian dollars for reference.

Where I'm at for costs, March 2, 2020:

2009 Silverado donor truck $800
Motor Mounts, Prothane 7509, $118
Motor mount adapters, ICT 551628, $56
Transmission mount, Energy Suspension 3.1108g $38
Exhaust manifolds and gaskets, GM Parts Direct, 2006-2009 TBSS, 12600527, 12600526, 2pcs. 12617944, $247
Driveshaft, local shop, reused 09 yoke, $300
Fuel tank, Brothers Trucks, BSGT069, $217
Sending unit, Brothers Trucks, STK72SU, $39

Total $1815 CDN

Re: 72 C20 LS Swap/Build
 

Some pics.

Me looking proud with my donor truck.

Taking out the old 350.

No engine.

4.8 pulled from 09.

350 vs 4.8

Re: 72 C20 LS Swap/Build
 

Some more pics.

09 wiring.

Test fitting the 4.8.

Passenger side with TBSS manifold test fit. Made in China.

Driver side with TBSS manifold test fit. Made in Canada. Weird but that's ok.

Shifter linkage from a 80's or 90's? Jimmy that my dad had kicking around. Made a bracket that bolts through the frame to hold the Jimmy bracket. Also ended up making a nylon bushing to adapt to the 72 rod. Works!

Re: 72 C20 LS Swap/Build
 

More pics.

Gas tank is out. 72 Blazer tank ordered from Brothers.

09 gas pedal in place. My dad did some welding and put in rivet nuts to bolt it in place.

Driveshaft is in. 09 yoke was used by the driveshaft shop.

Had to cut away some material at the bottom of this crossmember. The truck had a two piece shaft previously. We lifted up the back end of the truck to take all the weight off the wheels and there was around 1/8" of clearance for the shaft. At ride height it's around 3/4".

09 fuel pump module. Planning to use this in the 72 Blazer tank along these lines: https://ls1tech.com/forums/conversio...maro-tank.html

Re: 72 C20 LS Swap/Build
 

Looking good, Tanks for posting the basic cost of parts etc. You got a smokin deal on the donor truck. I would suggest you change brake pedal to 1 from a car that has pedal left of center.

Re: 72 C20 LS Swap/Build
 

That is a smokin deal on that donor! This is a good example of a budget-minded swap that will give you a solid running truck.

Re: 72 C20 LS Swap/Build
 

Yeah, very happy with the donor price. My dad scours kijiji (Canadian craigslist equivalent) daily.

The brake pedal offset would give more room for my size 13 work boots? Seems like a good idea.

Re: 72 C20 LS Swap/Build
 

I am about to do the same thing so I will be watching. I am a very cheap minded guy. I cannot bring myself to buy the Dirty Dingo mounts. How are the ICT working out?

Re: 72 C20 LS Swap/Build
 

The ICT adapters bolted up without any issues. I have the engine as far back as it can go ie. the forward most set of holes in the adapters. This coincided with a set of holes in the frame so that the transmission crossmember slid forward or maybe it was back and bolted right in with no drilling.

The motor mount bolts required a washer or two under the heads in two of the holes as there was block casting that they would have ran into and not seated fully.

Re: 72 C20 LS Swap/Build
 

Thank you! Do you plan on AC?

Re: 72 C20 LS Swap/Build
 

AC wouldn't fit in the stock location and my truck didn't have it so I'm just going to pass. I can always try to add it later on, but it's not a big priority - summer is short in Toronto!

Re: 72 C20 LS Swap/Build
 

That's what I figured. Kinda like Winter in Tampa. I don't need a heater.

Re: 72 C20 LS Swap/Build
 

What are you swapping into?

Not much to report until I get the gas tank in.

Re: 72 C20 LS Swap/Build
 

More parts on the way. Ordered some from Rock Auto. Some on ebay. Nicopp fuel/brake line from Walmart... All prices CAD $

2 rolls CNC-625 Nicopp 3/8" fuel/brake/trans line 25', $145
5 NUTS - Lower Transmission Cooler Line - GENUINE GM 10269715, $31
4 Oil line cooler connector, Dorman 800732, $27
4' Gates 27349 high pressure fuel hose, $16
2' Gates 27059 transmission hose, $6
Gates 355230 1972 C20 power steering pressure hose, $17

So running total as of March 10 is $2057 CDN. I haven't included shipping costs in some of these things while others were free.

Re: 72 C20 LS Swap/Build
 

I am getting ready to swap a 5.7 LS1 and 6 speed T56 into a 72 2WD Blazer. Stole everything I could from the doner before selling the carcass before I had to move. I wish I could have stole more. I will try to document everything in my thread. So far I have $700 in the motor and trans harness and computer. It was in a running car I bought. I drove it around for a while then had to move so I parted it out. I bought the motor mounts you specified from ICT. $34.99 with free shipping. They look nice.

Re: 72 C20 LS Swap/Build
 

nice progress:metal:, have you connected the tac wires yet? I am in the middle of swapping a 4.8/4L60E into my '86 square. any thoughts or direction would be greatly appreciated:smoke:

Re: 72 C20 LS Swap/Build
 

Thanks! Have not got to any wiring yet.

Things are a bit on pause while the virus takes over the world. I had ordered my gas tank through Brothers and it is in the US while I am in Canada unable to cross the border. Handful of other small parts are also there.

Re: 72 C20 LS Swap/Build
 

What is the drive shaft out of? Im looking for one to swap out my 2 piece for my ls swap on a 70 C10

Re: 72 C20 LS Swap/Build
 

The driveshaft was custom made, and re-used the yoke from the 09 driveshaft. The 09 shaft was aluminum, maybe 5" diameter and apparently could not be re-worked so a new steel one was made instead. It was $300 CAD.

Re: 72 C20 LS Swap/Build
 

Minor updates to the build.

I had planned to get my radiator modified to use for the swap by changing an inlet size and adding a steam port. The shop I took it to tested it and it was leaking all over the place, so there is no sense in trying to repair it. Looking at potentially ordering a rad and fans from a 2011 Camaro which are close in size and would run around $520CDN delivered to Canada. Cold Case was recommended but that would be upwards of $800CDN before shipping. Cost and reliability are the key issues for me - I don't care what it looks like so long as it keeps the engine cool and running.

My gas tank has been stranded in Buffalo since the lockdown began with no end in sight to the border closure. Hopefully I am able to get it shipped across the border at some point to keep things moving. I will be installing the 09 fuel pump module in a 72 tank under the bed.

We started a bit of wiring. Removed the pins related to AC since I am not running it. Keeping the stock 09 fuel pump, evap canister, o2 sensors and cats, so things are fairly stock and very little to remove.

I'm thinking I might go with HPtuners to be able to remove VATS and then potentially play around with tuning stuff. I'm pretty savvy at computer stuff but have no experience with tuning yet. Hopefully it's fun to mess around with.

Any opinions on this stuff is appreciated.

Re: 72 C20 LS Swap/Build
 

You can order a tank through nappa
Nice start on your truck

Re: 72 C20 LS Swap/Build
 

Ordered some more parts. I decided to go with a 2002 Camaro rad and fan. Both new are just shy of $400 CAD.

The gas tank is now on hand as well.

I have to order the S-10 number template for the speedometer as I have that on hand now too.

Still might get HPtuners to do the vats and tuning stuff.

Should be able to get the project moving forward again!

Re: 72 C20 LS Swap/Build
 

I haven't got it hooked up yet but I am going with the 1999 Trans Am radiator and fans as well as the Condenser. I am trying to figure out how to keep them in the mounts on the radiator though. Seems a large bump may send them skyward and out of the clips that hold them. I am using the stock harness for the TA for relays etc. Seems we both are on the same path.

Re: 72 C20 LS Swap/Build
 

Updating the costs so far:

2009 Silverado donor truck $800
Motor Mounts, Prothane 7509, $118
Motor mount adapters, ICT 551628, $56
Transmission mount, Energy Suspension 3.1108g $38
Exhaust manifolds and gaskets, GM Parts Direct, 2006-2009 TBSS, 12600527, 12600526, 2pcs. 12617944, $247
Driveshaft, local shop, reused 09 yoke, $300
Fuel tank, Brothers Trucks, BSGT069, $217
Sending unit, Brothers Trucks, STK72SU, $39
S10 gauge cluster, 1996, $35
2002 Camaro radiator, local shop, Spectra CU1485, $220
2002 Camaro fans, Amazon.ca, Dorman 620-634, $173
Oil cooler line connector, Rock Auto, Dorman 800732, $27
Fuel line hose, Rock Auto, Gates 27349, $16
Transmission/oil cooler hose, Rock Auto, Gates 27059, $6
Power steering pressure hose, Rock Auto, Gates 355230, $17


Total $2309 CDN

Sold $1125 worth of parts from the 09 donor along with the old 350/350, so net cost is $1184 CDN thus far.

Re: 72 C20 LS Swap/Build
 

Nice work so far. Subbed. Question, is there a special reason you decided to go with the fuel pump assembly from following thread and the brothers tank?

https://ls1tech.com/forums/conversio...maro-tank.html

.

I’m using the fuel pump module from my 09 donor Silverado and using the Brother’s tank since it appears relatively flat on top to be able to cut the circle in it. Same idea as the link you posted. I decided against using the stock tank and having an aftermarket pump and pressure regulator. Mostly I was concerned about the need to have baffles for the tank. The 09 fuel pump module takes care of that concern.
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The Trans Am radiator looks the same as the 02 Camaro. My dad who is doing most of the actual work (truck is in his garage) is thinking some rubber grommets on the bottom to support it. He mentioned that the top brackets might need to be modified as well. Might be working on it this weekend and will get some pics if we get that far.
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Re: 72 C20 LS Swap/Build
 

I almost did the exact same thing. But then I found the Tanks Inc. fuel pump assembly. It's in-tank and has a baffle pan. I used the corvette filter, super cheap, and it's also a regulator for the LS engine(stock). Same tank too.

2 things. You will want to drop the tank a little(see my thread if you want) so you don't have to clearance the bed cross rail too much. 2nd thing, check out this powernation episode. It's EXACTLY what your about to do - https://www.powernationtv.com/episod...ls-engine-swap


.

Re: 72 C20 LS Swap/Build
 

I had not come across the Tanks Inc. pump - the one with the reservoir tray. I take it that you are also using that in an under the bed tank? I had found a guy that modified his in cab tank, but I didn't want to bother with that.

Thanks for the video link. Yeah, that's the plan. Mine is a C20, so I don't know if there will be the same clearance issues, but dropping it a couple inches won't be a problem.

I am planning on doing something a bit unusual with the fuel fill. I found this post, #30 where the filler tube is routed all the way to the stock location to the under the bed tank. I like this since it keeps the original look and location as well as convenience next to the drivers side. I think the behind the taillight mounting is a bit weird and wouldn't want to have it in the bed floor.

Re: 72 C20 LS Swap/Build
 

Some recent work on the truck.

Modified the fuel tank to fit the 09 Silverado fuel pump. I had a 1/4" thick steel ring waterjet cut to weld to the tank which would allow the pump to be bolted down. The tank didn't have enough of a flat area to mount it, so a new pan was made and cut into it. Bolts were welded into the pan through the ring which act as studs to mount the pump. The ring wasn't really necessary, but reinforces the pan to provide a strong mounting location. The original 72 fuel sender was reused since it fit in the sender hole in the tank. The lines were brazed shut since it won't be carrying any fuel.

Re: 72 C20 LS Swap/Build
 

More.

The fuel tank ended up needing more clearance to allow the filler neck to get above the frame rail. The bed crossmember was notched, filled in and is now high enough to be out of the way.

The frame rail had to be heated and bent as well to get the neck above it.

Re: 72 C20 LS Swap/Build
 

More work.

My plan to run a long line to the original filler in the cab won't work due to the slope required and clearance for the suspension. So it is being routed to be behind the driver side wheel well on the side of the inner bed panel. There will be a steel tube that makes its way to the filler neck on the tank along with a Gates rubber 90 to connect it.

This is a work truck for me, so having something straightforward and functional is more important than hiding it behind a taillight or having a hole through the bed floor. I also didn't want to cut into the bed side to install a door since that would mean re-painting the truck which I cannot afford, nor want to do. It will be painted the same blue at least.

Re: 72 C20 LS Swap/Build
 

Last one for today.

Forgot that the gas filler will also have a lid made up to keep weather off it.

The Camaro rad is in. I ordered a set of 3 core radiator bushings and modified the 4 core brackets to fit them since the new rad is much smaller than the original 4 core. The new bushings also needed to be cut a bit to fit the rad snugly. They were cut on a diagonal and RTV'd into the brackets. Upper rad hose fits on from the 09 Silverado. Cooling lines are being bent up to get connected.

Once the fuel system is all connected, I suppose the focus will turn to the wiring. Was hoping that HP Tuners would have a Black Friday sale but no luck. Maybe Boxing Day..

Re: 72 C20 LS Swap/Build
 

All good work man! Question, I just finished my custom gas filler(see my thread), welded a vent in the cap neck. Also using rollover vent. Curious how your doing yours. Is that the OE filler your using(already has the in-cap vent that follows the filler line to tank)?

Re: 72 C20 LS Swap/Build
 

Yeah, I'm using the 09 Silverado filler neck and vent tube from the donor truck. I don't really know much about venting so will have to do some reading - presumably GM included a rollover vent?

Re: 72 C20 LS Swap/Build
 

Cool man, you will be happy with a stock unit like that. Here's how I understand it all. You need 2 vents. 1 vent for filling your tank, the other vent is for driving and sitting, it's for heat expansion and such. Fill vent allows air to push out during filling so you can use the gas pump nozzle full throttle ;).

Here's the safety part. Small vent for heat expansion, for safety reasons, gets the rollover valve. Fill vent needs to be connected to your filler cap so the gas nozzle extends past it allowing air to escape back out through it, but seals it off with cap during operation. If you get into a wreck, rollover valve closes the small valve so fuel doesn't spill out and filler cap seals the filler vent. Safe.

I would say that's the general idea behind it all for safety and function. There are more sciences to it you can read about elsewhere :thumbs:

:chevy:

Re: 72 C20 LS Swap/Build
 

I had a good conversation with a lady at boyds welding. I have the old style tank from them that doesn't have the 5/8 line fill vent next to the 2" fill. I bought a retro fit adaptor from Boyds that goes from 1/2 npt fitting to 5/8 hose barb. Then I'll drill a hole and use self tappers to secure to tank and then I'll be able to run the 5/8" line to my filler neck from an older s10.

Re: 72 C20 LS Swap/Build
 

After an unintentional summer hiatus, work is going again on the truck!

The gas tank is all welded, pressure tested, wired and mostly plumbed. Everything seems to fit nicely including the fill which involves an S bend tube, a rubber 90 and some straight hose. Might pick up an installation tool for the nylon fuel lines and fittings. I've ordered parts from FMSI since they are local for that stuff.

Wiring cleanup has been in progress too. Everything should be set to the gas tank and fuel pump. Underhood stuff is close. Gauge swap to the S10 speedo is mostly done. Still more work to do at the dash. I still don't quite get how the ignition 'talks' to the PCM yet...

There's an instrument panel connector with some vague sounding wires that remain, along with a VSS wire. I added in a VSS wire to the X1 connector but a bit uncertain about that.

I'm quite confused about the alternator after reading the other day that it needs a GCBM and BCM to have the ability to change voltage output based on load. I don't have either module, however that function sounds nice compared to its default at 13.8V. Keeping the alternator stock is appealing from a parts availability standpoint. I've read a thread about changing out the regulator on the back, but that isn't stock anymore... There was some other thread about a PWM signal generator device... Any suggestions would be helpful.

Re: 72 C20 LS Swap/Build
 

You've been quite busy for having a hiatus..!!

Re: 72 C20 LS Swap/Build
 

Big news - the truck runs!!!! :metal::metal:

The wiring proved to be rather tricky to get that Gen 4 engine to run, but we perservered. I started a thread about it here where the specifics are discussed: http://67-72chevytrucks.com/vboard/s...d.php?t=827216

We took it for a little spin after cleaning up all the underhood wires and it is so smooth and quiet! There is some programming yet in order to get the speedo and tach reading - so far nothing. Still need to clean up the dash wiring as well and connect the oil pressure sender - it started leaking oil on my shoes once it finally started to crank, so it was temporarily capped off.

The alternator is outputting 13.8V which is its default or limp mode and I would like the variable output capability. I'm not running a BCM, so will need to figure out where to run the wires from the negative cable sensor.