The Covered Wagon- My '89 Suburban Overland/camping rig build

After much discussion between SWMBO and I, it has been decided that the 400 C.I. small block in my shop will be transplanted into my Daily Driver, a 1989 V1500 Suburban. One, it's a direct swap with minimal fuss, two, it saves us money, and three, the 'Burb is probably my favorite conveyance ever.

So, the starting point- Your standard, run-of-the-mill 4x4 Suburban. Current mileage is 95k, and I'm the third owner.

Pros- Low mileage, already lifted 4", reliable, straight axles, factory oil cooler, cheap parts, makes cool noises.

Cons- Needs a bit of interior TLC, minor rust on some areas, needs some bodywork, TBI...

The TBI is by far the worst of the cons. I've got maybe 200hp at the crank, if I'm lucky. This barge weighs 6,000lbs... I need moar power!!! The 400 will go a long way in fixing the anemic powerplant issue, to the tune of ~350hp and ~425lb.ft of torque. 

The current plan- Build the 400, install it, convert from TBI to Carburetor, remove anything in the engine bay that does not say "Awesome camping rig", and go from there. On the list is a complete powertrain rebuild, aiming for reliability and durability first and foremost. The interior will be upgraded as I go, and body work will be saved for last. As always, advice, opinions, random thoughts, etc. are more than welcome. This will be my first major build, although I've been a mechanic most of my life.

I grew up in the back of one of those barn door burbs.  Love them!  My recomendation is after you get the project moving on its own power, to take it camping quickly.   See what works and what doesn't and go from there.  I see the best results when I institute a 48 hour rule on my projects after they are on the road.  If it can't be fixed/upgraded in 48 hours....it's saved for the full teardown/rebuild. 

I might be getting old (hint, I'm getting old) but I've come to appreciate quiet trucks in the woods. I'd rather lose a few HP and cut the noise in half. 

Other than that, are you going to be sleeping inside? Tent? Rooftop tent? Traveling solo or with groups? When the first motor is out clean and maybe paint the engine bay. Life is so much better when you don't get greasy every time you open the hood, especially when you're in the woods away from hot water and soap. Speaking of which, how about plumbing in a heat exchanger  when you do the swap for unlimited hot water on the trail? Give me hot water and a fridge and I'll never go home. Did I mention that I'm getting old? 

In reply to mazdeuce :

Mostly, it'll be just me and the kids out adventuring; when Mrs. Recon is along, we take the motorhome. We're talking one or two nights out, nothing crazy. I've already got a tent that the kids love to sleep in, so the rest of it is pretty simple. Our camping game is pretty strong, I'm just looking at ways to have fun with the kids. As for noises,  the 400 will actually be pretty quiet on the trail. most of the torque should start showing up at about 2k rpm, and in low, it ought to idle almost anywhere. Painting the engine bay is on the list, I'll probably wind up pulling the front clip to do the swap. It'll make life easier where the truck is already lifted. 

Love a square Suburban. Can't wait for the swap. 

yaaaaaaaaassssssssssssss

Mrs VCH has a '91, same body style.  Love these old, boxy burbs.

Hers has the 350- rated at around 190 HP.  But its a very usable 190 horses.  And Torque.   We towed a small camper up to Massachusettes and back, with 2 kids, a dog, and the back full of gear, averaging 65-70 mph and around 14 mpg.  That's NOT TERRIBLE. 

I'd reconsider the 400 transplant...especially since you'll probably end up with only around 300 HP, and be lucky to pull down double-digit fuel economy.  

The other  issue- the 700R4 is a fine transmission.  But, stick it behind anything making mild-built 400 small black levels of power, and it's going to start getting unhappy.  A large, efficient cooler is a bare minimum requirement for any sort of towing use.  

The missus' 'Burb has 190k on it, and the trans is starting to do that "shift into D, wait 3-4 seconds for it to clunk into gear" thing.  When it goes out we'll look into a "built" 700R4 for it, and if you're transplanting a 400, you may wish to consider the same.  

volvoclearinghouse said:

Mrs VCH has a '91, same body style.  Love these old, boxy burbs.

Hers has the 350- rated at around 190 HP.  But its a very usable 190 horses.  And Torque.   We towed a small camper up to Massachusettes and back, with 2 kids, a dog, and the back full of gear, averaging 65-70 mph and around 14 mpg.  That's NOT TERRIBLE. 

I'd reconsider the 400 transplant...especially since you'll probably end up with only around 300 HP, and be lucky to pull down double-digit fuel economy.  

Ignore this mans' comments.

Keep the TBI.....get a 454SS throttle body(toss the injectors) ......an edelbrock SBC mutipoint FI manifold ......1.6 ratio rocker arms.....keep your cam LSA around 110-112 and a chip from Brian Harris at TBIchips.com....voila driveabilty and possibly 1-2 mpg increase.

New trans will definitely be going into it, as I am well aware of the issues that the 700r4/4L60E series of transmissions have. I’m getting a beefed up unit from bow tie overdrives that’s good for 600lb.ft of torque. As far as carb vs TBI, the carburetor is non-negotiable. I’ve owned several carbureted vehicles, and they’re just as driveable as fuelie rigs when you take the time to tune them right from the get go. Call me old fashioned, I guess...

what you need is a 4l80E or 4l85e

In reply to fidelity101 :

I’ve thought about it. Trick is getting everything matched up to the transfer case...

Recon1342 said:

In reply to fidelity101 :

I’ve thought about it. Trick is getting everything matched up to the transfer case...

And talking to the carburetor.  4L8x transmissions only came on FI equipped cars.  

No question- I'm a carburetor guy, too.  But TBI is basically an electronic carburetor.  And (so far, knock wood, I have two TBI equipped vehicles- a 454-powered dually and the 350 suburban) it just works.  

One more thing... (/Columbo)

With TBI, you can run a catalytic converter and (along with the other TBI mods described above) you maintain good driveability and the exhaust doesn't stink like an NHRA track.  When we bought the Missus' 'Burb some ham-fist had cut off the cat; we installed a Turbo Cat (~$40) and the difference in the exhaust stench was noticeable afterwards.  Since we haul around 2 kids with this thing, that was a concern.  

We also put in the 2-1 Y-pipe, which makes for a much neater installation underneath, and supposedly better flow.  A 95K mile 350 is just getting broken in- there's a lot you can do for minimal money and time compared to a full-blown engine/trans swap.  

Then stick that 400 in something fun, like a Chevy II.  

In reply to volvoclearinghouse :

Buzzkill.  The Burb is my fun rig. It has to be, cause I’ve got a bunch of kids.

The problem with TBI is that you get so little bang for your buck. For driveability, it’s phenomenal; for mods and power, it stinks. As soon as you go north of 250hp on a TBI 350, you have to start looking into new fuel pumps, injectors, and a host of other mods, plus re-flashing the ECM, all to provide enough fuel to keep you from burning a hole in the pistons. I can do the same thing with a 750cfm carburetor, a fuel regulator to bump 12psi down to 4psi, and a decent distributor. Plus, it’s infinitely more tuneable.

Besides, Chevy used to put 400’s in the Suburban, and everybody else builds 350’s or 383’s. 

In reply to Recon1342 :

Hey, I get it- we have kids, too.  Probably younger than yours (mine are 3 yrs and 8 months) and we take them camping, too.  I guess we're spoiled- my wife has a 350-powered Camaro and that's our fun car.  (Yes, you can fit two full-sized adults in the front seat, and two child's seats in the back seat, of a 1968 Camaro!).  It seems to me that Carbs and TBI have the same basic tuning requirements, its just a matter of whether one goes about it electrically or mechanically.  As was mentioned before, stick a TBI unit from a 454 on a 350 and you should have plenty of flow.  

I also don't get so hung up on HP numbers anymore.  Especially in something like a Suburban.  How often is the engine going to spin north of 3000 RPM?  Almost never.  Of course, with 15% more displacement, a 400 is going to out-torque a 350.  If this is your fun build, then go for it- my mentality is more that the Sub is an appliance, and I focus the performance effort on our other crappy old jalopies.  :-P  So you can disregard anything I say.  Except about the 700R4.  ;-)

In reply to volvoclearinghouse :

I have six, ranging in age from 14 years old down to two. The minivan is the appliance, and the Burb is my daily. I have to have a fun/quirky vehicle, otherwise I lose interest. Mrs Recon is more patient saint than active participant, but she understands what makes me tick. 

You’re 200% correct on the 700r4, I’ll freely admit. It’s planned for.

Keep your eyes peeled for a serpentine setup off a '90 or newer TBI truck (or 4.3 S10, I think).  Fidelity101 turned me onto this swap in his frankenburban build.  I think your '89 has stamped steel accessory brackets...And they work fine (I have that in my '89 shortbed 2wd).  But aluminum brackets off the '90+ trucks are slick and simple.  That's what I put in my 4x4 Suburban and I couldn't be happier with the decision.  

In reply to ClemSparks :

The donor motor I pulled the heads from is a ‘99... 

Just remember, if you go with the serpentine belts, the water pump and fan spin backwards, so you'll need new ones for a serpentine belt engine.  

Unrelated, holy carp, 6 kids?  No wonder your wife has the patience of a saint.  We about pull our hair out every night with 2.  

Recon1342 said:

In reply to volvoclearinghouse :

I have six, ranging in age from 14 years old down to two. The minivan is the appliance, and the Burb is my daily. I have to have a fun/quirky vehicle, otherwise I lose interest. Mrs Recon is more patient saint than active participant, but she understands what makes me tick. 

You’re 200% correct on the 700r4, I’ll freely admit. It’s planned for.

I love that people like you exist to make me look reasonable.

After the third, it gets a lot easier. My 14 year old is an awesome helper...

The 400 started out as a bare block, so it’s a blank slate as far as accessories go. It’s a wonderful feeling...

Recon1342 said:

After the third, it gets a lot easier. 

I'm just gonna go ahead and take your word on that...  

Not much to report on the Burb, at the moment...

pulled the factory spare out and converted the cavity to roadside equipment storage; I’ve got my jumper cables, tow strap and shackles, folding shovel, tire iron, and handyman jack neatly organized now, instead of rattling around the cargo area. Next up will be fabricating an elevated breather box for the transfer case and transmission breathers, so I can locate them on the firewall instead of under the chassis. I also plan on drawing up plans for bumpers. Rear will have a swing out tire mount, and front will have light tabs and a 2” receiver for a winch cradle. 

Slowly just chugging away...