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1988 K20 Suburban Build Thread

88Burb17

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Mar 6, 2022
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Location
Texas
Hey everyone! This is my first post here on CK5, and I'd like to share my Suburban. This first post will be a long one because I'd like to document my first year of owning the burb before I start posting build updates

Specs:
1988 Chevy K20 Suburban
Carbed 350 (I'll get to that later)
TH400
NP208
14 Bolt FF
3.73 gears (as told by PO, still haven't confirmed)
35x12.5R15
4 inch lift (blocks in the back)

I purchased the Burb from a gentleman in west Texas about a year ago. It had sat unregistered since 2012 and the PO had just installed a "brand new" SBC 400 before I had purchased it. He told me that the PO had taken out all of the TBI wiring and put a carb on a SBC that he had pulled from an old Blazer and had rebuilt. After doing some more inspecting, It looks like all of the TBI wiring is still there and just zip tied to random places in the engine bay.

My fiancé and I drove out about 4 hours and 45 minutes one way to look at this truck and we ended up falling in love as soon as we saw it. I then took a huge risk and drove it back another 4 hours and 45 minutes with no issues and smooth sailing (besides the 8 mpg)

Heres the first pic I took
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The drive home was great and it was nothing but smiles all night, I even took a pic of my new pile of junk next to my older piles of junk the next morning.
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The next morning after I bought the truck, I got almost all the way to work before we started having problems. As I got to the gate at work, the truck stalled on me and died while I was in line. I was able to eventually start it back up and got another quarter mile down the road before it died out on me again. The truck would crank and crank and crank but wouldn't turn over. I chased some of the fuses and wires around the entire truck until my friends and I finally figured out that I had some how melted the ignition coil inside the distributor cap
See pic below:
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I bought a new ignition coil and that got me through the next couple of days. Looking back, I should have double checked where the PO had hooked up the ignition wire and the speedo wire but I believe that's what led to my small demise again about 3 days after the initial meltdown.
I went to take my fiancé out on a date and we got about 30 minutes down the highway and the same exact thing happened again. This time I went straight to the distributor and checked the coil and sure enough, same problem and another melted coil. This time I pulled up the wiring diagram and noticed that the ignition wire and speedo wire were backwards (don't ask me how that worked in the first place because I have no idea) So I switched them and made sure all my grounds were correct. I also noticed that the ignition wire was stretched and had bare wire exposed and rubbing on the firewall which is what I believe might have been part of my issue. I field repaired that with some electrical tape and added it to my mental list of things to change out when I got home. I haven't had any issues with it since so I am assuming that it was both of those issues causing me to burn through ignition coils. I now keep a spare coil and an extra extinguisher in the truck because I know that I was extremely lucky to not have the truck burn down both times.

Here are some more pics I took of the truck
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Truck ran great for about a month, I used it as my daily while I was working on the wiring on my '84. Then one night on my way home on the highway, I heard a sound coming from the motor that could only be described as a screwdriver in a pencil sharpener followed by a very loud and hollow sounding pop. I get out of the truck on the side of the highway and see a hole in my oil pan and oil and bits all over the place along with the freeze plug cap that goes over the cam shaft. Had it towed home and kicked myself all night. Next day I pulled the oil pan and found a mess of metal all over the place. Bits of the rods and rod caps in the oil pan and the camshaft broken in half. The motor was very obviously locked up so I couldn't rotate it around to see much else without completely tearing down the block.
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I wish I could have gotten a pic of the cam in half but it was just too hard to get the camera in a good place to see it.

I decided that I was going to swap out the motor from my '84. Its a 350 with a 4 bolt main, not my favorite option but definitely my best option for the time being. At the time I had made up my mind that I would LS swap the '84 so this was going to be my kick in the butt to get it going. With the help of my amazing friend, we started the swap in the parking lot of my apartment complex on a Saturday and had the motor in the suburban by Sunday.

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Here is a pic from where the cam popped the freeze plug off
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My only issue was that we didn't button everything up on Sunday and when I came home from work on Monday, the apartment complex had both of the trucks towed and I had to go find them. This was a major setback financially and also took a lot of time. In retrospect, this was 100% my fault and I should have towed it to my buddies house to start. the tow company ended up breaking the U joints when they disconnected the driveshaft. All in all it cost me about $800 to get my trucks out of the yard.

I had them both towed to my buddies house where we finished up the suburban.

This pic shows my buddies 78 El Camino and his 72 C10
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You could tell that we were definitely the cool kids on the block :D

Now I forgot to mention that at some point in this process I had taken off the military 37's and put the 35's on from my '84. The Humvee tires were really cool and I loved the white rims with the hubcaps but the tires were from '91 and were dry rotting like crazy. Living right off of Fort Hood made me think that it would be really easy to get new ones but that was not the case at all, and finding tires that fit on 16.5 rims are really expensive nowadays.


We finished the truck the day before the wedding which was great because it was our getaway vehicle!
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(yes I do know that there's a really cool spot on the front bumper for a license plate and yes I did loose the bolts that hold the license plate in that nifty little spot so that's why it's zip tied)

I got lucky with getting the truck back together in time and I also got really lucky finding a lady who enjoys these just as much as I do.
IMG_4520.JPG


From December to February we got my '84 put back together with a 454 that I traded for. It was a sweet little 3/4 ton single cab long bed with a 454 and a SM465 and I wish I could have kept it. I ended up selling it to fund our move from Texas to Wisconsin and still kick myself for not being able to make it work. We moved up to Wisconsin in February and I towed a 6x12 U-Haul the entire way.

Here's the pup's favorite spot
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Here we are all loaded up and ready to head north!
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I'll have to find my weight ticket but I believe the truck and trailer together were around 7,840lbs with the U-Haul being 1,920lbs of that

Here we are in Little Rock, surprisingly in a parking garage that's actually tall enough for me to fit! Blew an alternator just outside Dallas but that only set me back an hour before we were back on the road.
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At this point in the trip I had found out 2 new things about the truck.
#1: The windshield wipers work for about 10 minutes before they randomly stop in the middle of the windshield
#2: In true Texas truck format, the heater does not work.

This last one made the last push to my moms house in Indiana and up to our new place in Wisconsin miserable and cold. I had lots of blankets in the front seat with me and kicked the dog out to the warm car with my wife.

Here we are finally in Indiana in the middle of snow storm.
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Didn't take any pics when we got to WI sadly. Ended the trip with 1530 miles and about 6.5 mpg. I used a GPS speedometer app to calculate speed and milage and put it all in a spreadsheet. I am thankful that we only had one minor setback and did this trip before gas skyrocketed.

I will continue to update this thread as I work on the truck more and as I start to thaw out up here. Next project is figuring out why I'm only getting 6-7 mpg with no trailer and no heavy weight in the back.

Thank y'all for reading my short novel!

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Welcome, you're going to fit right in!

Save the oldies. I have a 86 and a 90 burb. And just recently bought a 79 K5.

Full time job, like having kids! Lol
 
Welcome, you're going to fit right in!

Save the oldies. I have a 86 and a 90 burb. And just recently bought a 79 K5.

Full time job, like having kids! Lol
I love them all like my kids! Unfortunately I had to sell the '78 burb as well because I just didn't have the funds and garage to tackle all the rust and body issues that I didn't see when I initially bought it. I have told my self from now on I wont be selling any more!
 
Going to put the TBI back on it?

Martin
Not sure yet, I've only ever ran a carb and I don't exactly know what all the PO took off/ bypassed when they got rid of TBI. I'm sure its not that complicated and it would probably help with my fuel milage issue a little bit but I haven't had a ton of time to do research on it. I'm also currently looking to get a big block for this thing so I can tow the camper that my wife has been wanting to get so I'm a little hesitant on messing with the tbi right this second.
 
My tbi sbc in my suburban netted 6.5 to 7 mpg as well. Something was wrong but I couldn't find the issue, my qjet 454 gets 9-10 running down the highway at speed limit.
 
My 91 dodge with TBI gets 9-10 and so does my K20 with a 350 and Holley Truck Avenger….the dodge has 4.10s and the Chevy has 4.56s
 
My 91 dodge with TBI gets 9-10 and so does my K20 with a 350 and Holley Truck Avenger….the dodge has 4.10s and the Chevy has 4.56s
Yeah I probably just need to accept the fact that my 6,000lb tool shed is not as fuel efficient as I want it to be and I would probably be better off investing in some wind sails instead :D
 
What speed were you running on your move? I've found that 65 is my trucks happy place on the highway. Over that and I'm pushing 3k rpm and mileage really suffers.
I'm on 38 14.5 tires tho, so anything over 6 I'm really happy with.
 
What speed were you running on your move? I've found that 65 is my trucks happy place on the highway. Over that and I'm pushing 3k rpm and mileage really suffers.
I'm on 38 14.5 tires tho, so anything over 6 I'm really happy with.
I was running about 65-70 most of the way, surprisingly I didn’t see much of a change in mpg towing vs empty but I think it’s because I’m comparing my highway miles towing to my empty city driving
 
Ended up moving down to Indiana and the burb ran great again. It was only about a 5-hour drive and we got about 7.5 mpg for the drive which is pretty similar to our move from Texas to Wisconsin. I did notice some bogging when I put my foot into it but I haven't done too much sleuthing around yet to figure out what that might be. I did some basic checks, I made sure the accelerator pump was adjusted correctly and I noticed that the bogging only happens under load. When I'm in park I can rev the engine and I have no issues at all. I also noticed that there is a very random and intermittent miss when idling. I will do some more digging and maybe take some videos in case I can't figure it out.
 
Another small update

I finally pulled the sagging headliner out in lots of pieces. At one point it had a CB antenna in the middle of the roof and when they took it out they didn't seal the hole properly so water slowly leaked in and absolutely ruined the headliner.

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Need to figure out what I want to do with that since I have been seeing that apparently LMC only sells headliners for rear AC trucks. If anyone has any thoughts or ideas please let me know.


I also finally pulled out the old rubber mat from the trunk area that had the insulation underneath because it was torn and getting the insulation all over the place every time I put something back there.

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I need to tackle some of that surface rust and then I think I might pull the trigger on the Lizard Skin sound deadening/insulation kit. I would just rhino line it but my wife and I plan on camping out of this thing so I think Ill just go ahead and get the insulation too.
 
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