1971 C20 "LS Swap"

[JustToxic]

Well, I started a new project, except this isn't my truck. Taking a 1971 C20 Camper Special Truck and swapping it to a LS. My step dad has had this truck for over 10 years now, truck came from California, only rust on it is from the battery, battery tray and inner fender is ate up. Going to be taking out the crate 350 / TH350 combo, when new making about 240 hp. Putting in a 6.0 Liter LQ9 / 4L80 combo, after a few modifications 500 hp. Going to be keeping the fuel injection on the LS and keeping the Camper Special dual tanks. Once I'm done with the swap, its going to a body shop to have a new paint job put on it. Stay tuned and I'll try to post pics along the way.

[JustToxic]

Got the transmission back from Scott at Trick Tuning and fabrication, so I decided to do all the mock up and test fitting with a 4.8 I picked up the other weekend. So when the 6.0 shows up I can just swap motors. Picked up a set of weld in poly mounts for the LS and a Energy Suspension trans mount. Got to make up some bolt in mounts and the LS/4L80 will be ready for bolt in. I'll take some more pictures along the way. Been mainly doing a bunch of cleaning and un interesting stuff.

[JustToxic]

Spent some time in the garage last night making up bolt in mounts. Was able to use existing holes in the upper frame and only had to drill two additional holes in the cross-member for the lower to bolt to. Tried to fit the headers last night, found the long tubes I got after doing a bunch of reading, wont work so I have to either make clearance for the headers, cut and modify them, or get shorty's to go on. Still have to drill new holes for the trans cross-member, which I'm surprised I didn't have to modify, and get that bolted in. Next I'll move on to fuel tanks and plumbing for the fuel injection.

[rjs53]

This is pretty cool. Looks like tour making everything work with out buy a kit or aftermarket parts. Keep us posted on progress.

[JustToxic]

Fuel tanks finished welded, and the tank liner is drying in the picture.

[JustToxic]

Well after having header fitment issues, I had to cut apart the mounts I previously made and remade them. Now just have to clearance the frame a bit for the passenger side header.

The LQ9 6.0 I picked up had seen better days, when my engine builder pulled it apart it had dropped a valve seat into a piston and the piston ended up in the oil pan. So the block in waiting to get bored .060 over to clear up the groves. So the waiting game is now even longer then before. I decided to use the 4.8 I have laying around to mock up as much as I possibly can.

What I didn't get pictures of was the fuel tank modifications, and the routing of the fuel lines to the switching valve. Still have a few feet fuel line to run and that will be complete. Took measurements for the driveshaft so I can have that cut down while I wait. Next will be having the A/C lines modified to fit the new compressor.

[JustToxic]

Got out in the shop some more this week. Mounted the headers on both sides, drivers side fit nice. Passenger side, had to clearance the frame a bit to clear the larger tube primary's. Going to be working on the wiring and finishing the fuel system next.

[JustToxic]

Started making the LS wiring fit the '71 wiring. Step dad is putting bucket seat in and a center console down the road, so I decided to steal the glove box space. I plan on making a custom glove box insert for him when were all done with the install. My engine builder/tuner has a rough reprogram done on the PCM were using, wiring has been modified so it is easy 3 wire hook up. Trying to hide all the extra wires in a Factory A/C truck is harder then you'd think.

[cornerstone]

With those dual tanks and a more efficient v8 what do you expect your range to be when tanks are full? Cool project btw...

[JustToxic]

You know I'm not actually sure. With the old SBC my step dad never used the passenger tank due to a leak. I'm not sure of the total mileage it will get with both tanks but the new engine should be getting around 14-16 mpg, compared to the 7 mpg he was getting from the old set up. He mainly uses the truck for camping and hauling stuff, but with the new set up I'm sure I'll see him driving around town a lot more. Thanks.

[JustToxic]

Been putting some hours in plumbing new fuel lines and cleaning up the wiring. Still have a few fuel lines left to make up. Got the new Energy Suspension Poly body mounts installed over the weekend. The switching valve and fuel pump are wired up and installed. Got word back from my engine builder and machine shop, said it would be about 2 weeks and I'll get the engine back. Got all my exhaust parts in from ACE Race and Magnaflow, I'll start that project later this week. In the middle of cleaning up some Trailing arms and adding some Energy Suspension Poly bushings, I'll also be putting poly bushing in the track bar. I couldn't get my phone to send pictures, so I'll add some pictures later.

[JustToxic]

For the last week (a few hours after work each night) I've been plugging away at the custom stainless steel exhaust. I wish I could have found one that was 3" and fit the way I wanted it to, but like everything on this swap I decided just to fab it up instead of buying pre-made. Bought a set of long tube headers for a Camaro w/a 6.2, put a V-band clamp on the collector and started the exhaust off of that. Here's what I have so far, pardon the torch cuts that I still have to clean up. I got to the axle before I ran out of pipe, still waiting on the rest of the pipe to show up.

[JustToxic]

Here are a few more of the exhaust. I'm using a set of Magnaflow mufflers, 3" center in offset out.

Also, made up the trans linkage. Used part of the factory rod and modified a spare Th350 linkage I had laying around. Used a mini heim joint at the trans side. Factory column shift works great with the 4L80.

[cornerstone]

Nice work on the exhaust man. I've been looking all over the forum for a few days to find the pictures you just posted, lol. Im not quite ready yet but want to be prepared ahead of time. I know it will be tight but thats the routing I plan to use for my truck also. Where did you buy your pipe and v bands from? if you don't mind me asking...

[JustToxic]

Thanks cornerstone! I got all of my exhaust parts from aceraceparts.com, good company to deal with.

[JustToxic]

Well I got the engine back end of last week. Spent the weekend putting it in. Just have to finish up a few things, axle back exhaust, wiring, and plumbing.

[JustToxic]

Well, we are nearing the finish line on this project. Just have to button up a few things before it heads over to the tuners shop so he can tune it on his dyno.

[JustToxic]

Made the final touches on the truck tonight, just have to put the hood on it and send it to get tuned. Hopefully I can get some good video to post of it on the dyno at the tuners shop. Finished up the intake, which was bought to fit a 2002 Silverado but I modified it and added a 45 to fit this truck better. Cut a hole in the core support just in front of the filter so it has a good supply of air. Also, modified the newer a/c lines to fit the 71 a/c system. Wiring harness tucked down nice out of the way and made for a nice clean finish. Gotta remember to clean up the stainless steel headers/exhaust before we start it so it doesn't show the figure prints.

[JustToxic]

Got the tailpipes all finished up and mounted in. I polished the ends up for a nice finish. Didn't go with a mirror finish, just a slightly brighter brushed finish then the rest of the exhaust.

[rjs53]

Very nice job! What are you doing for gauges? That seems to be the question I see. I know some are using an S10 cluster on the back of the c10 dash and some a phone or old tablet or IPad set up.

[JustToxic]

Thank you. I can't remember exactly but I'm pretty sure he decided to go with New Vintage USA gauge cluster. They look pretty close to stock and will take the inputs from the PCM to work. I'll post some stuff on here about them when I get them from my step dad.

[rowdy11]

Excellent work! Do you have any pics of the fuel lines? What did you use? Did you also use an in-tank pump or inline? Which brand by chance?

[JustToxic]

Thank you rowdy11! I couldn't get any good pictures of the fuel lines, I'll see if I can snap a couple now that it is out of my shop. I used 3/8 aluminum line with -6AN fittings for the feed line, and for the return lines I used 5/16 aluminum line with fuel injection hose clamps. The fuel pump is a Walbro inline pump, I placed it right in front of the tank switching valve which is (cover your ears) a Ford Medium duty truck tank switching valve. I'm using 2 -6AN metal screen fuel filters placed at the fuel tank outlet.

[JustToxic]

Here are some pictures of the fuel lines.

[JustToxic]

Here are a few video's of it running. Hopefully have a video of it on the dyno here shortly.

https://youtu.be/boBn_kOuvzk

https://youtu.be/E_KYKPFIcn8