1972 C20 Suburban LS1 4L60E
09-13-2013, 06:14 PM
#1
1972 C20 Suburban LS1 4L60E After a few months of parts scrounging, Im finally starting my official build thread!
Car: 1972 C20 Suburban. 3/4 Ton, 2wd, 3 door. Still has the factory 402 big block and TH350 trans. Its getting a solid 9 mpg and the acceleration of a tug boat.
Mods: The truck is factory stock at the moment but its my daily driver so the goal is to swap a built LS1 with a 4L60E transmission. The engine will remain carb'd for the sake of simplicity and old school cool. Other additions include a fully rebuilt brake system and a vintage A/C system. At some point I also plan to suicide the rear door on the passenger side. Lastly, I plan on running a completely hidden and separate 4 speaker audio system in the glove box with speakers under the bench seats while retaining the stand alone, original AM/FM single speaker radio in the dash.
Stay tuned!!
Factory cool!!
Car: 1972 C20 Suburban. 3/4 Ton, 2wd, 3 door. Still has the factory 402 big block and TH350 trans. Its getting a solid 9 mpg and the acceleration of a tug boat.
Mods: The truck is factory stock at the moment but its my daily driver so the goal is to swap a built LS1 with a 4L60E transmission. The engine will remain carb'd for the sake of simplicity and old school cool. Other additions include a fully rebuilt brake system and a vintage A/C system. At some point I also plan to suicide the rear door on the passenger side. Lastly, I plan on running a completely hidden and separate 4 speaker audio system in the glove box with speakers under the bench seats while retaining the stand alone, original AM/FM single speaker radio in the dash.
Stay tuned!!
Factory cool!!
09-13-2013, 06:21 PM
#2
First up, new brakes and tires and wheels. I didnt take any pics of the brakes because all I did was replace all of the original junk with new pieces. New discs, calipers, and pads in the front, completely rebuilt drums in the back along with a new master cylinder and booster under the hood. The only thing that remains are the factory hard lines. 4 bottles of brake fluid with the Motive power bleeder later and I have crystal clear fluid at all 4 corners and a perfectly firm pedal.
In addition, I scrounged some Ford (I know, shoot me) van, 8 lug wheels from the junk yard for $30 bucks each. Theyre the same 16 inches as the factory pieces but at 7 inches wide, theyre a full inch wider than stock and accept the factory dog dish hub caps. I decided to pain them black with a set of BFG white letters to fill out the wheel wells a bit better than stock with 275/65/16 tires.
In addition, I scrounged some Ford (I know, shoot me) van, 8 lug wheels from the junk yard for $30 bucks each. Theyre the same 16 inches as the factory pieces but at 7 inches wide, theyre a full inch wider than stock and accept the factory dog dish hub caps. I decided to pain them black with a set of BFG white letters to fill out the wheel wells a bit better than stock with 275/65/16 tires.
09-13-2013, 06:37 PM
#3
And now for the good stuff....
I picked up a rebuild, 2002 LS1 long block for $1000. Its the factory block with a balanced factory rotating assembly. I grabbed a set of 243 heads for $300 on CraigsList that I sent down to Airflow Induction to have their rebuild done for $425 with a valve job, new seats and retainers and new springs good to .650 lift. I bought a custom spec'd cam from Vinci Performance that's 216/224 585/585 112 specifically for the carb'd application. I found the rebuild 4L60E with the torque converter, flywheel, remote filter, cooler, and hard lines locally for $500. The guy I bought it from was going to run it in a '69 suburban so all of the pre-bent hard lines for the cooler and filter are set up for my frame. Additionally I got a 3 piece drive shaft from him that fits the LS swap into the suburban for $40. The polished aluminum valve covers were an ebay find for $90, and the shorty headers were another ebay purchase at $190....not sure they'll fit, but for the price I figured the gamble was worth it. The Edelbrock intake was another CraigsList find for $200 and the 600cfm Edelbrock car only has a few dyno pulls on it, I traded my buddy a pair of ATV ramps for it. More to come later...just put in a big order with Summit for all the bolts and gaskets to finish assembling the short block!
I picked up a rebuild, 2002 LS1 long block for $1000. Its the factory block with a balanced factory rotating assembly. I grabbed a set of 243 heads for $300 on CraigsList that I sent down to Airflow Induction to have their rebuild done for $425 with a valve job, new seats and retainers and new springs good to .650 lift. I bought a custom spec'd cam from Vinci Performance that's 216/224 585/585 112 specifically for the carb'd application. I found the rebuild 4L60E with the torque converter, flywheel, remote filter, cooler, and hard lines locally for $500. The guy I bought it from was going to run it in a '69 suburban so all of the pre-bent hard lines for the cooler and filter are set up for my frame. Additionally I got a 3 piece drive shaft from him that fits the LS swap into the suburban for $40. The polished aluminum valve covers were an ebay find for $90, and the shorty headers were another ebay purchase at $190....not sure they'll fit, but for the price I figured the gamble was worth it. The Edelbrock intake was another CraigsList find for $200 and the 600cfm Edelbrock car only has a few dyno pulls on it, I traded my buddy a pair of ATV ramps for it. More to come later...just put in a big order with Summit for all the bolts and gaskets to finish assembling the short block!
09-13-2013, 07:08 PM
#5
Unfortunately there will be an interruption in the build....I deploy to Korea for 6 months in November so the goal is to get the motor built by then and start the conversion as soon as I get back in May. Fortunately I already have a buyer for the 402/TH350....so that should free up a significant amount of cash once I get back in the states next spring!
09-14-2013, 04:39 PM
#6
Thanks for the service. Damn nice Burban. I ALWAYS wanted one, still do. b Should be a great swap when done.
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10-16-2013, 08:09 PM
#8
Motor finally complete. LS1 block with factory rotating assembly (crank balanced, new piston rings), 243 heads milled to 61cc chambers and rebuilt, 216/224 585 585 112 Vinci Performance camshaft.
My deployment has been pushed back until mid-December and I managed to barrow my buddy's car while he's deployed so the Suburban goes under the knife next weekend. Stay tuned for updates
My deployment has been pushed back until mid-December and I managed to barrow my buddy's car while he's deployed so the Suburban goes under the knife next weekend. Stay tuned for updates
10-28-2013, 08:44 PM
#9
Some progress finally...
Working in a 1-car garage definitely makes it a challenge, especially with a car this long
The motor actually came out far more easily than anticipated. We were able to remove the engine and trans as 1 unit by just pulling the radiator and removing the fan....plenty of room
The end result....getting the factory A/C system out was actually more time consuming than getting the motor out!
The dead mouse tally for the dash was 3, but after much cutting and swearing, I had the entire factory A/C system and wiring harness removed. Both will be replaced with vintage A/C and painless harness.
Someone was not impressed with the progress......
Next up this week is to get the CPP motor mounts installed, get the new KYB shocks installed, and start routing the painless harness. Hope to get the motor and trans into the car Sunday afternoon.
Working in a 1-car garage definitely makes it a challenge, especially with a car this long
The motor actually came out far more easily than anticipated. We were able to remove the engine and trans as 1 unit by just pulling the radiator and removing the fan....plenty of room
The end result....getting the factory A/C system out was actually more time consuming than getting the motor out!
The dead mouse tally for the dash was 3, but after much cutting and swearing, I had the entire factory A/C system and wiring harness removed. Both will be replaced with vintage A/C and painless harness.
Someone was not impressed with the progress......
Next up this week is to get the CPP motor mounts installed, get the new KYB shocks installed, and start routing the painless harness. Hope to get the motor and trans into the car Sunday afternoon.
10-28-2013, 09:10 PM
#11
TECH Fanatic
iTrader: (7)
I have never seen one of these with the rear air option...very cool...may I ask why you didn't try the factory A/C first, before installing the Vintage system...???
Very cool build...subscribed.
Very cool build...subscribed.
10-29-2013, 06:38 AM
#12
The factory AC system was pretty weak, and recharging it with the old style coolant is expensive. Additionally, the majority of the tubing for the system was dry rotted and mice had taken over the heater core and everything behind the dash. Lastly, it was a pretty complex system of tubing, both under the dash and in the engine bay. The Vintage A/C system is far simpler and makes for a much cleaner install. Im going to retain the shroud for the factory rear A/C and use it to mount some decent speakers so that I can upgrade the sound system without having it visible.
11-03-2013, 03:34 PM
#13
Made some decent progress today, although nothing terribly exciting as Im still waiting for my CPP motor mounts to arrive.
Got my new KYB MonoMax shocks installed at all 4 corners. This is only significant in that it is the first new item to go back onto the car. Thus far its been all tear down. Should be a solid improvement once back on the road over the worthless factory units that looked like they might not have been replaced since it left the factory in '72.
Got the rusty exhaust cut out and all the original fuel hard lines. I will be building a return style system from the tank forward using all new lines and fittings along with a Mallory fuel pump and regulator and a Holly 650 carb.
Also got the Holley accessory brackets mounted on the motor. This is a really solid set up, and idiot proof. Im very pleased with the quality and the factory look. Thats a Sanden D5 compressor for the vintage A/C system.
Installed the AutoMeter wet-line oil pressure adapter to feed the factory oil pressure gage.
Also installed the AutoMeter water temp sensor for the single wire factory water temp gage. I decided to run it here so that I can run the wire into the loom along with the alternator harness to minimize the number of wires running around the engine bay.
Got my new KYB MonoMax shocks installed at all 4 corners. This is only significant in that it is the first new item to go back onto the car. Thus far its been all tear down. Should be a solid improvement once back on the road over the worthless factory units that looked like they might not have been replaced since it left the factory in '72.
Got the rusty exhaust cut out and all the original fuel hard lines. I will be building a return style system from the tank forward using all new lines and fittings along with a Mallory fuel pump and regulator and a Holly 650 carb.
Also got the Holley accessory brackets mounted on the motor. This is a really solid set up, and idiot proof. Im very pleased with the quality and the factory look. Thats a Sanden D5 compressor for the vintage A/C system.
Installed the AutoMeter wet-line oil pressure adapter to feed the factory oil pressure gage.
Also installed the AutoMeter water temp sensor for the single wire factory water temp gage. I decided to run it here so that I can run the wire into the loom along with the alternator harness to minimize the number of wires running around the engine bay.
11-06-2013, 06:20 AM
#15
wow, that is awesome! it looks like you've taken yours a bit farther than I have! This is actually my daily driver so I didnt want to invest a whole lot of time or money beautifying something that sits out in the parking lot all day every day. Im also using this as a first run at the LS swap as I plan on doing the same thing with a 68-69 Corvette roadster when I get back from deployment. Thats been m dream car for a long while 
11-06-2013, 10:54 AM
#20
Sure did....a numbers matching big block suburban is worth exactly as much as a non numbers matching suburban....and one with an LS motor and overdrive trans can be driven and enjoyed every day without worrying about breaking down or getting 8 mpg!!