GMT400 suburban questions

[peasy]

Hi all I was hoping someone could answer some questions for me.

I am looking at buying a 92-99 suburban - I am particularly attracted to the TBI engine for it's simplicity and similar fuel mileage to the more complicated/expensive vortec version, so that has me looking at 92-95 k1500 suburbans around my area. Because of the salt related rust in Mn I am hoping to find an out of state rust-free k2500 in the future to swap in the TBI 350 from the suburban I will be purchasing soon.

now the question:
Will the 4l80e in a 97-99 k2500 suburban bolt up and work with a TBI 350 motor?

I want the 97-99 specifically for the internal upgrades to the transmission, the passenger front airbag, OBD2 and r134 freon. 3/4 ton suburbans are hard to find and it's even harder to find one that doesn't have a 454 in it.

Is this do-able or is it a pipe dream? should I be planning on using a pre-96 3/4 ton for the swap? Or should I just get a 97-99 half ton and deal with the vortec?

p.s.(planning for putting goodyear duratracs on it, a good winch and pair of bumpers on it..maybe some suspension "beefing-up" and a hydroboost upgrade in the far future but I want to save those for the 3/4 ton)


All comments are appreciated thanks !

also: im not completely sold on the duratracs...they seem to be great for what I need in regards to rain/snow/mud but people say they are pricier than others and wear out fast? Any other suggestions for tires for 8th gen suburbans? Living in north Minnesota near the great lakes we get a lot of precipitation..

 

[justcuz]

A 4L80E will certainly bolt up, but that is not you only consideration. The 80 trans may not be compatible with the 60's computer. You also have to install a 32 spline input or change your t-case
I have to look more into this but I thought all 93 and up 3/4 ton Suburbans had a 4L80E in them, or were they just in big blocks and diesels?

 

[RoughRiderZ71]

I think all 3/4 and 1 tons bad 4L80s in them. I would just use the Vortec. More power, better fuel economy too. And there are fixes for the fuel injection system, in the form of an updated injection assembly with electronic injectors as opposed to the stock poppet valves.

Sent from my Vortec-powered Droid Turbo using Tapatalk

 

[peasy]

I would just use the Vortec.

hmm probably good advice. Looks like I'll be a tech-in-training at a ford dealership soon, so a more advanced EFI system shouldn't scare me away..

I'm gona keep my eye out for a 97-99 k1500 suburban...and when I have the means and ca$h I'll look at a no-salt state for a k2500 to swap in a 5.7, since most are big block.

 

[justcuz]

If your going to work for Ford, you may find a neat deal on an Excursion too.

 

[firefighterm9]

My 97 k2500 suburban has 350 and 4l80e

 

[peasy]

If your going to work for Ford, you may find a neat deal on an Excursion too.

I'd rather have the IFS to be honest...northern MN/WI roads are freaking terrible. Concrete slabs with rebar inlaid, sometimes they have a good inch gap between them

also between the choice of V10 and powerstroke diesel I'd much rather have a small block 350; the GM power-train seems to be a much more reliable/cheaper option

While I've got some folk's attention.. Does anyone have any suggestions for good AT tires for far north MN conditions? We get a good deal of rain and snow, and I assume mud will definitely be a thing when going down trails. So far the only thing I've been looking at it GY Duratracs, but alternatives would be nice to those expensive tires that I've read people complain about tread wearing too quickly.

 

[justcuz]

I don't disagree with you at all about the engines. I've always thought an Excursion with a 6.0/4L80E/NP241 would make a nice combo for a camping/adventure mobile.

Here in the west the possibilities of roads going bad from sudden washouts from rain events are common and unless you have 12" of travel with your IFS a solid axle is better in many cases.

Chris, in his thread about 475 miles of dirt road travel in Utah and 14 hours of digging I think mentioned that he preferred the Goodyear MTR over the BFG AT.

 

[peasy]

roads going bad from sudden washouts from rain events are common and unless you have 12" of travel with your IFS a solid axle is better in many cases.

Chris, in his thread about 475 miles of dirt road travel in Utah and 14 hours of digging I think mentioned that he preferred the Goodyear MTR over the BFG AT.

excursions have 12" travel stock??! If I ever get serious about technical trail riding I'd probably just get a toy to tow behind the suburban - some SFA truck or a jeep. Solid axles are a pain for a daily driver, and they really limit your choice of vehicle.. The Excursion seems like a great chassis but the idea of buying a truck and planning to completely swap powertrain is way out of my budget, especially if I'm getting 10 mpg with a v10 until then.

As much as I'd like a mud tire, they all seem to suck in rain - those goodyear mtr look like they have little to no sipes. I live right off Lake Superior so rain is a constant, as well as snow and ice 1/2 the year. The front runners as less pricey alternatives to Duratracs, which I've read about in other threads, are:

Nokian Rotiiva AT
cooper at w
hankook Dynapro AT-M

Those BFG AT are so popular I'm starting to believe a lot of it is hype, and they look like they'd be better suited to southern more sandy conditions - I've read some people saying they give less than desirable performance on wet and icy roads.

Anyone have experience with the cooper or nokians?

while doing my research I've had a hard time finding any crash-safety data on the gmt400s, but the 2000-2004 suburban looks to have great safety rating. Does anyone have any suggestions on OBS vs NBS? It looks like 2004 has hydroboost stock -- newer sounds better, but how the hell am I gona get a 14 bolt with the g80 under there if they have rear coil springs???

 

[MTCK]

We run cooper St maxx year round on our work trucks and get them siped. They do very well in inclimate weather and are pretty tough.

Having owned TBI and Vortec 5.7's and now a Vortec 7.4 (all trucks not suburbans) I never saw a large delta in fuel mileage between them. I would be looking for a 96-99 with a big block and 10.5" rear. 4L80E's swallow a lot of power and a suburban is a big heavy rig, so that little 350 will be working its tail off. Then load it up and hitch up a trailer...

 

[peasy]

Thanks for input on the tire - but from what I've heard there can be as much as 5 mpg difference between SBC and BBC on the highway...thats a big deal on a 1000 mile trip.

I've got myself so damn confuddled with options, now I'm considering gmt800s...but the price has me liking these 400s still hah

 

[MTCK]

GMT800 would be good too. I'd get an 8.1! In all seriousness it comes down to how you use it. Most folks going on adventures load the piss out of their rigs, hook to a trailer and bomb off into the sunset. I averaged 8.6 mpg in my V3500 with a tbi 350. I haven't used a full pair of tanks yet with the new motor, but I expect 10 mpg range. That's because I'm always hauling a load or pulling a heavy trailer. The 350 was out of its league and the 454 isn't hardly working. Idling down the freeway comparing a 4.10 geared 454 and say a 3.42 geared 350 I bet you could see 5 mpg difference. Good luck. Go test drive some trucks.

 

[peasy]

Go test drive some trucks.

hah! great advice

thanks:smiley_drive:


How I use it? It'll be a daily driver for my work commute and maybe used on long trips. Definitely want to do some over-landing/light trail riding as well.

Maybe I should look for a 00-03 2500 with the 6.0 - I get 4l80e, 14 bolt rear, bigger brakes and the hydroboost...

 

[Martinjmpr]

It's not model specific but I have a personal rule I try to follow when it comes to vehicles: NEVER buy the first year run of any particular model or make. It's always better to buy the last year of the previous model run than the first year of a new generation.
.
So if you can't afford at least a 2001 or 2002, then go with a really loaded up 1998 or 99. As another plus, it seems like towards the end of a particular generation, things that were previously options become standard, so you get a better-equipped vehicle.
.
2500's are nice but from my experience, not easy to find and they often have high mileage. I passed on a low-mileage, low-price 2500 because it had the 8.1 - WAAY too much engine for what I need!

 

[peasy]

It's not model specific but I have a personal rule I try to follow when it comes to vehicles: NEVER buy the first year run of any particular model or make. It's always better to buy the last year of the previous model run than the first year of a new generation.
.
So if you can't afford at least a 2001 or 2002, then go with a really loaded up 1998 or 99. As another plus, it seems like towards the end of a particular generation, things that were previously options become standard, so you get a better-equipped vehicle.
.
2500's are nice but from my experience, not easy to find and they often have high mileage. I passed on a low-mileage, low-price 2500 because it had the 8.1 - WAAY too much engine for what I need!

Found a 6.0l 2500 suburban, he's asking 6500$ and its 140k - thats lower than most 1500s I've seen. The only thing I'm worried about with that is the MPG - most people don't ever even reach 15 MPG with the 6.0, and the 5.3 Is supposed to get closer to 18 mpg... I wonder if it'd be worth it to get the 1500 model and then swap in the SF 14 bolt, and another transmission... the 4l80e would be mostly bolt-in but after that would I be getting similar mileage to the 2500? hmmm...maybe if I can find a good deal on a 02-03 2500 I could plan a nv4500/zf6 swap in the future... I bet that'd net some MPG