Morphing a Sierra with a Silverado

New to this site and not sure if this is the correct forum. Mods please move if you feel it belongs somewhere else. Basically I'm taking two wrecked trucks and combining them into one good truck. This will be a thread about all the steps it took me to combine a Sierra with a Silverado.

It all started Wed August 13 when I bought a rolled 2004 Silverado. The plan was to take the 6.0l lq4/4l80E out of the truck put a procharger on it and swap it into my firebird. I bought the truck not knowing if it would run. The way it was hit I was sure that the engine would turn over.

http://i225.photobucket.com/albums/d...d054bucket.jpg

I towed it home thursday and on friday I started working on it. The first problem was that when the truck was upside down it turned the intake manifold into an oil pan. Now that the truck was right side up I could get all the oil out.

First was to pull the spark plugs and see if the motor would turn over. I pulled all eight and turned the crank with a socket. Oil came spewing out of all eight holes. That was pretty bad but at least it turned freely. I then put a battery on it and cranked it with the plugs out. More oil came out. After a few cranks I put all the plugs back in and hooked up the wires.

I had to pull the air intake out to clean everything. The air filter was soaking with oil, the maf was covered, and the tube inbetween the throttle body and maf was still full. After cleaning all the oil out and spraying a maf sensor cleaner on the maf I put a new filter in and hooked everything back up.

I filled it with 3 gallons of gas and put the battery back on. Checked all the fluids and added when necessary. I turned the key a couple of times to prime the fuel rail and pump. Then I started the truck and it ran the first time.

Immediately it started smoking. And kept smoking and kept smoking. I ran it for about 20 mins and it still never stopped smoking! But it was running so i drove it off the street and into the driveway and called it a night.

nice, well figure there is about 6 or 7 quarts of oil soaked into everything on the upper half of the motor where oil isnt usually supposed to be soaked into, so when ur burning oil it will put with smoke. So did you figure out which truck you are going to use the frame and everything?

should be a cool project, keep us posted with lots of pics.

Yea the intake is nice and clean but the exhaust is another story. I didn't clean any of it out of the exhaust. I think the longer I run it the farther on down the exhaust it starts burning oil. Plus I don't know if the cat is ruined after being drowned in oil. I've probably run the engine for a total of 45 mins and it is still smokin!

So i was content with the 04 Silverado and the plan to pull the engine was still going good. I decided to mess around with the body work on the truck. I have never fixed anything that bad and I couldn't make it any worse right? So I tore out the interior and hooked up the porta power and started fixing things. I was starting to get somewhere and I got all the doors to close again and latch correctly.

http://i225.photobucket.com/albums/d...d058bucket.jpg

Keep in mind that I wasn't planning on keepin or fixin the truck. I was just getting some practice with the porta power. Well I guess I pushed the porta power to the limits because when I went to push the roof back into place I blew a seal. It was fun while it lasted.

Next I started doing an inventory on what parts I could sell from the silverado. After everything was said and done I figured I could keep the engine/trans and get my money back from parting the truck out.

Roughly a week and a half later I was wandering on the net and saw something that caught my eye. It was an 04 Sierra with the lq4/4l80E. I took a look at the truck in person and was totally blown away. It was totally different from the Sado. It had all the luxury options and upgraded options. It really was in good condition too.

http://i225.photobucket.com/albums/d...9a14bucket.jpg

I had never owned a truck before the Sado and now I was thinkn of buying another one. But the Sierra was different from the Sado. It was a crew cab instead of extenda cab. The Sado was a work truck stripped down model and the Sierra was the cruising road trip and towing model.

At that moment I knew what I had to do. Morph the Sierra with the Sado.
Things really started looking good especially when I saw where it was hit.

http://i225.photobucket.com/albums/d...9a12bucket.jpg


With my little knowledge of trucks it seemed like a perfect match. Take the front end from the Sado and put it on the Sierra. What could go wrong right? They were both 6.0l/4l80E 2004 2wd trucks. So I did it. On August 27 I bought the Sierra. Just two weeks after buying the Sado. My biggest challenge would be to explain to my wife why I drained our savings account to buy two wrecked trucks. But the damage was done. I now owned two trucks. A 2004 Silverado and a 2004 Sierra.

First step was to determine how bad the damage was. Obviously the white truck was toast. The frame was probably ok but the cab was munched and the bed side was hit pretty good. It would never be the same.

Next I looked at the Sierra to see how badly it was damaged. At initial inspection it looked as if it hit something tall and didn't crunch the frame. It was hard to tell with everything smashed into a Sierra cube. So i began to tear the front end off.

http://i225.photobucket.com/albums/d...h/1head064.jpg
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You can see I started to find out some interesting things once I pried away the twisted metal. One major thing was the broken intake manifold. The radiator and condenser were wrapped around the fan. If you look closely you can see where the fan hub tore apart from threaded stud in the middle. The water pump shaft pushed through the rear cover of the pump about an inch.

It was bad. I didnt think the motor was touched at all. From under the car I looked and it didn't seem like it hit the crankshaft pulley but I couldn't see on top. Now I know it got creamed. Things were starting to get bad but not impossible.

The alternator was torn off the mounting bracket and the idler pulley was bent. The alternator looked ok but it didn't spin anymore. The crappy plastic tensioner was also trashed. But obviously that didn't matter because even the metal parts were mangled.

You can see in the second pic how close the bumper came to taking out the wheel and the control arm. There is a small scuff on the a-arm but that was from me trying to remove other busted pieces.

Not only was the radiator support pushed back but it was torn in half at the middle. I was starting to get worried about the frame now.

I had a friend come over to look at the truck for fun. He laughed at both of them and told me it would be months till I got them fixed. Yea whatever, we'll see I told him. But then he asked if the motor was supposed to be leaning back in the engine bay. I had noticed that earlier and took a look at the Sado. There was a slight tilt to the Sado's motor but not much. Looking again at Sierra I saw the angle that the motor sat back at was quite large compared to the white truck.

http://i225.photobucket.com/albums/d...head079a10.jpg

:whack: O damn! What did I get myself into. This was getting worse and worse. I still wasn't hopelessly lost but I was getting close to it. So most of the front accessories were trash, intake shot, radiator support and all related components were thrashed, engine tilted, and whatever else I hadn't discovered yet.

Was the frame hit? Was I wrong about how high the damage really was. I still thought it would be ok at this point. Just a little more to tear apart. Bend all the fragged metal out of the way so I could get to the bumper bolts and then I would know for sure.

http://i225.photobucket.com/albums/d...3abhead066.jpg

Do you guys think the frame is damaged at this point by looking at the pics?

I'm betting you'll need a Sawzall or maybe even a plasma cutter :)

Between the two, you've got at least 1 good frame, but you might need to get friendly with an autobody professional.

I betcha the block is still good. Keep tearing into it and keep us informed.

After tearing down the front end I got to what I was looking for. The frame was just like I thought. Perfect! Well almost, the bumper brackets in the center were slightly tweaked. Nothing a larger hammer couldn't fix. It was a good clean hit that got close to the frame but didn't mash it. The only thing that got smashed was the passenger front brake line.

http://i225.photobucket.com/albums/d...a04door009.jpg

So my next task was to fix that brake line. No sweat I had the Sado to take parts off of. Before I disconnected anything I took a look at both trucks to compare brake lines. This is when I made a big discovery about the differences between Silverados and Sierras.

It may be common knowledge here on the forums but I found out that in 2004 Silverados sit higher than Sierras.

I discovered this because on the Silverado the brake lines run on top of the frame rail to the abs block. But on Sierras the lines run on the sides of the frame rails because there is no space on top between the body and the frame.

The brake lines won't switch over from a Sado to a Sierra. They will however switch from a Sierra to a Sado.

http://i225.photobucket.com/albums/d...b04door031.jpg

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http://i225.photobucket.com/albums/d...04door-054.jpg

So after that discovery I decided to go to the junk yard and find a replacement and just splice the brake line at the radiator support. I ended up finding a 2007 Silverado that basically just the frame and brake lines were left.

The strange thing about this Sado was that the brake lines looked just like the ones for the Sierra. They were routed along the side and not the top of the frame rail. Maybe the junkyard screwed up and miss labeled the truck or maybe sometime later all the trucks used the same frame. I'm not sure but you can see that in 2004 they are different.

So I bought the line and took it home to put it on the Sierra. I guess on the new body style the radiator crossmember is closer to the engine than in 2004. The brake line was the right diameter and the fittings were the correct thread but the line was short about 3 inches from the radiator crossmember. No big deal again I just rebent the line a little to make it fit. These brake lines were very soft and you could bend them with your hands. I was just careful not to kink them. It turned out perfect. I redrilled one of the holes for the plastic clips but that was all.

http://i225.photobucket.com/albums/d...e04door045.jpg

Quote:

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Originally Posted by AdioSS

I'm betting you'll need a Sawzall or maybe even a plasma cutter :)

Between the two, you've got at least 1 good frame, but you might need to get friendly with an autobody professional.

I betcha the block is still good. Keep tearing into it and keep us informed.

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As bad as the front end was smashed all I needed was a large pry bar and an air ratchet. Ill use the Sawzall and plasma cutter when I chop the Silverado up!

O I forgot to mention that the crankshaft pulley, a/c and power steering pump were untouched in the crash. Awesome. That means there is a good chance that the engine is still good. I figure that the water pump took the brunt of the hit and just pushed against the iron block. Which is attached to the trans which is supported by rubber mounts.

I ended replacing the engine mounts with the Silverado ones. The rubber was good on the engine mounts but the brackets were hammered!

http://i225.photobucket.com/albums/d...f04door043.jpg

The trans crossmember is bent and so is that large block piece that is between the trans and the crossmember. I haven't gotten around to swapping that out yet.

The only thing im worried about now is the driveshafts and the output shaft housing of the trans. I took a look underneath and they didn't seem bad. The carrier bearing was pushed back though about 1/2." Im guessing it needs at least a new output shaft housing seal but other than that I think its ok. I will take a second look and make sure. Do you think the driveshafts have enough flex room in them to be ok?

Damn dude...you've got a lot of work done! Nice write-up too...

Ok, as for the drivetrain on the GMC...consider it trashed. I would not reuse or try to fix anything. There should be enough flex in the driveline to where the rear end should still be good. I would take the motor, motor mounts, tranny, and driveshaft out of the GMC and replace it with the Chevy stuff. Of course you will need to get a new CCSB driveshaft for the GMC. I would save the motor and tranny from the GMC to use as your own parts stock.

From the looks of the frame, you are good--just swap over everything from the Chevy that you take off the GMC. It should be a pretty straight forward swap.

Good work--keep us updated!

Sry about this newb question. What is a CCSB driveshaft?

I need to post some more pics to try to catch up to where I am today. Maybe this weekend i'll get caught up here on the forums. Thanks for the encouragement.

CCSB stands for Crew Cab Short Bed

After swapping the motor mounts I later swapped in a new trans mount along with the crossmember. I swapped intake manifolds. Broken one for the good. I swapped the ps pulley and alt bracket. I used the same ps pump. Its nice that you can leave it hanging while you take the bracket out. I used the alt. from the other truck and swapped out the water pumps. Its awesome that the trucks use the o-ringed water pump seals instead of the gaskets.

I took the radiator support off the Sado and transferred it to the Sierra. I left everything attached and just removed two bolts for the support. I disconnected all the cooler lines and reconnected them on the Sierra. Looking really good at this point.

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Next snag was the fan shroud. Since the Sado sat higher the fan shroud needed adjustment. The engine stays in the same place relative to the frame on both trucks. But the radiator support sits higher on the Sado. It is an identical support but since it is higher the fan shroud is different. So I had to cut clearance on the shroud. I will eventually need a Sierra fan shroud but this will get me by until then.

It was the same story when I put the fenders on. The fender well liners are longer for the Sado so when they went on the Sierra they needed to be trimmed. There is a molding line that made a good place to start cutting. After that it only needed clearance around the front of the a-arm.

http://i225.photobucket.com/albums/d...oor2016web.jpg

http://i225.photobucket.com/albums/d...oor2022web.jpg

After that was taken care of. I spent the entire weekend lining up both fenders and the hood. There was a total of about 25 attach fenders, take off, adjust bracket or add shim, then re-attach fender sequences. Hood didn't have as much adjustment but fit nicely.

The bumper went on fairly easy but of course I ran into another problem. The top plastic piece was larger to compensate for the height of the Sado. So of course it didnt fit on the shorter Sierra. I took of the plastic piece and it fit nicely. I wonder if there is a low profile piece that fits on the Sado bumper? I'm not sure exactly how I'm going to get around this problem yet. At least it is chrome underneath.

http://i225.photobucket.com/albums/d...oor2020web.jpg

http://i225.photobucket.com/albums/d...oor2025web.jpg

So finally I'm caught up to today on the forums. Today I checked and rechecked all fluids. Spark plugs were replaced and I only destroyed two coil wires while trying to get them off. Of course they didn't use anti-seize on the plugs when they changed them. No stripped threads though! New oil and filter, new air filter, and an optima battery. I bought a fuel filter and couldn't find it on the truck. After searching the forums I realized why I need to take it back. I ain't droppn the tank to replace the filter.

After I hooked up the battery I turned the key on and off to prime the fuel system. I removed the top hose on the radiator and filled from there. Hopefully no air is trapped in the system. I said a prayer and turned the key. It started first time! Hell yea and it sounded good too. I looked at the exhaust and it is a flowmaster cat back with true duals. I let it run for a couple seconds then turned it off. Checked all the fluids and topped off as necessary. Started it again and let it warm up. No overheating yet! I had to keep checking the trans fluid. I eventually caught up with the trans oil pump and got it topped off. Closer each day!

wow you really are making progress on this transformation! congrats and keep up the good work!

It's comin along good, I didn't even know there was that much difference in the Chev and GM

Wow...you dont waste time!!!

congrats on the combination of the trucks!!!

hope all keeps goin your way!

dang thats awesome. Looking good, sweet to see that you got one truck out of two. You sure the fuel filter isnt on the drivers side frame rail facing the inside of the frame?? Thats where mine was it was super easy to change, guess i only have a 1500 though.

I want some vids! and more pics.

keep up the awesome work

Quote:

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Originally Posted by 99sierra4x4

dang thats awesome. Looking good, sweet to see that you got one truck out of two. You sure the fuel filter isnt on the drivers side frame rail facing the inside of the frame?? Thats where mine was it was super easy to change, guess i only have a 1500 though.

I want some vids! and more pics.

keep up the awesome work

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i think the 03 and up only have the in tank filter

^^^^^ Yea in tank lifetime filter. I suppose you just change the filter when the pump goes? We will all find out in a couple of years right?

Forgot to mention that I had the windshield replaced. Today I fit all the lights and grill. The connectors were exactly the same as the Silverado. Only difference is there are no hookups for the foglights. So I will just tie them out of the way in case I want to use them one day. Its looking like a truck now!

http://i225.photobucket.com/albums/d...oor2027web.jpg

http://i225.photobucket.com/albums/d...oor2030web.jpg

You can see in the above picture how close the grill comes to the top of the bumper. I'm still not sure how to get around this because the holes in the bumper are going to drive me nuts. I may try sectioning the plastic bumper piece and then plastic weld it back together. Then paint it the color of the body along with the fender opening pieces. But as you can see the clearance is tight.

2003's have an inline filter...so do the 2004's.

your bumper problem. see if you can pick a halfton bumper cap and have it painted when you do the rest the paintwork it should fit and look pretty good

looking good. what color are you going to paint the whole thing?

Wow. I wish I had that much free time.

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Originally Posted by zeake

Wow. I wish I had that much free time.

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Hahah! Yea right free time. We all have the same 24 hours in a day right? I have a full time job a wife and kid and don't work on Sundays. Where do I get time to do this? I'll just say i'm very tired from getting 4 to 5 hrs of sleep a night! It was a crazy thrash to get it done by this Saturday. Once i'm finished then i'll take a good long break and just enjoy the truck for awhile.