7.4L 1990s era Chevy/GMC V8 Suburbans opinions??

C

CharlesInCharge

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Considering two possible (or maybe more) late 1990s era V8 7.4L Chevy or GMC Suburbans. Very powerful gas hogs, but great for what they seemed to be. That is reliable workhorse camping and towing rigs. I might want to turn mine into a excursion type camping mobile on wheels. I'm not sure, but I love the body style and look of that 4x4 rig. A few locally sub $9k and 100-150k miles. Yes, terrible fuel economy.

So, what says the crowd? Durable, rugged, maintenance intense, junk, unreliable, monsters, gas hogs??? Frank opinions wanted. Thanks.
 
It depends on what you want out of it. Bottom line it's still a Chevy Big Block, a 4L80E transmission, a NP 241 transfer case, and 3/4 ton 8 bolt wheels running gear, although I'm not sure if the rear is a semi float 14 bolt or the more desirable full floating rear end. All the right base parts are there to do what you want. If you are adding a lot of weight to make it a great camping rig, this is the platform you want.
 
Had a '97 GMC Suburban 2500 not too long ago; biggest issue I had was with the Multec injectors. Ended up installing a set of marine injectors Trav helped me out with. But other than that, it was solid. The engine definitely wasn't as powerful as one would expect, however, but it could definitely tow.
 
Unless you really need the capacity of the 8 lug 454, get a 1500 with the Vortec 350. Being lighter weight it's probably just as quick.
 
Had a 1997 K1500, loved it (it's my name on this site). Great truck, very solid. Not the 454, but my buddy had the 2500 with 454 - same year. He drove it all over the country and had no issues except for the AC compressor and rear evap (both starting leaking due to age and corrosion). Interior isn't the best, lot's of cheap plastic that will break over time (AC vents, knobs, door handles, etc). But the main running gear is super solid and won't leave you stranded anywhere (just do your normal maintenance).

If you can get one that inspects out okay, I would recommend it. For camping in it though, it doesn't have a lot of insulation and will get cold quickly - condensation inside will build up quick too.

As a tow rig, expect 5 to 7 MPG. Mine had a 42 gallon tank and got expensive to fill at $4.00 a gallon every 210 miles. Your mileage may vary though.
 
I paid $2000 for a 2003 Suburban Z71 and there is another guy or two on here that got similar deals. That would give you a heck of a budget to do what you want.. if i were seriously shopping i would get the same era as mine but a 2500 series with a 6.0L.

With that $9K budget you could fly down south and get a good soccer mom unit
 
Those engines no longer apply to emissions so what I'd recommend you do is get that engine tuned because it's been neutered very badly for performance and even fuel economy for lower emissions. Those things with a tune can make a lot more power and get some more mpgs at the cost of a penguin or two.
 
Depends what you're really after at this point.

Driveline is basic and solid; typical GM of that era.

Pre-96 (probably 90-95) all those 454's were absolute dogs. Can't kill them because they just didn't make any power (stock).

(96-99) was probably the best of that body style. At the body change in (01?) you get the 8.1 or 6.0; both were fine. Overall these are still desirable trucks/body style.

Personal choice but if you're really wanting to make something out of one, the 75-89 Squarebody trucks you can make/adapt virtually any latemodel driveline into it pretty easily now so options are wide open. Budget friendly LS swaps aren't a headache by any means now.
 
The frames are junk in that era of gm truck. If you can find one that isn’t rotten in the back end you are lucky.

I am going to have to plate mine to make it able to tow.
 
Stock - awful.

With a top end kit (heads cam intake ) they can be pretty cool.
 
Terrible gas mileage (they didn't come with a 42 gallon tank for nothing). The towing mileage noted above (5-7 MPG) is what our units got towing large enclosed trailers. Underwhelming power by today's standards. Body and frame cancer was an issue after 10 years on our fleet units.
 
I have a 98 K3500 with the 7.4L/4L80E and its been pretty reliable. I bought it in 2007 with 94,000 miles on it and it now has 122,000. Some of the gauges in the instrument cluster are kind of wonky and it's not the quietest engine but it pulls anything I need it to pull.

It did break down on me recently and it was the coolant temp sensor, the one for the engine management and not the one for the gauge.

I get around 12-13 mpg empty and 8-9 towing. I'm sure a suburban would get a little worse since it's a heavier vehicle.
 
Any opinions of the 96-99 year models with the 7.4L. I don't care about gas mileage, buying a 454 isn't done for fuel economy.

There's a nice example nearby for about $8 grand.
 
CharlesInCharge said:
Any opinions of the 96-99 year models with the 7.4L. I don't care about gas mileage, buying a 454 isn't done for fuel economy.

There's a nice example nearby for about $8 grand.
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I say go for it! Like I mentioned earlier, the only real issue are the injectors which can be upgraded. They have the tendency to leak, which causes hard starts with a lot of black smoke out the exhaust, but other than that, they are solid.
 
CheezWhiz said:
i don’t think it is quite true though. a 632 would be a tall deck, likely with raised exhaust port heads. the OP should make the sensible choice and go with a little 540.
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I like the tall decks (10.2") because you can stuff a longer con-rod in it without getting the piston pin in the ring pack.
 
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