7.4 info request

[stutaeng]

If the info I've found on the web is correct:

1996 Vortec 7.4 is:
290hp @ 4000
410 ft lb @ 3200

2002 Triton V10 6.8
310hp @ 4250
425 ft lb @ 3250

Assuming each has been properly maintained, I don't think the small differences in the ratings would be very noticeable while towing a trailer. The Ford V10 operates how everyone has described the 7.4 making a lot of power down low and tapering off quickly as the RPM builds. The V10 really doesn't do much more after 3000 rpm than make a lot of noise. Ford programming does well at holding a gear to use the torque rather than downshifting.

The Excursion we have is a 2wd and has 4.30 gears, giving it a towing capacity of 10,500 pounds. It has coolers for the transmission, engine oil, and power steering. Our camper weight varies a bit depending on what we are taking with us, but is usually right around 9,000 pounds. I weighed the Excursion empty and it was 7,260 pounds, although I don't remember how much fuel was in it. I understand this is a Chevy forum, and I prefer Chevy over Ford a bit, but in all honestly that Excursion is a brute and does quite well pulling the camper. Having a family-hauling-grocery-getter appearance makes it a real sleeper when it comes to working.

Now that all of that's been said, and based on what I've read here, I should enjoy a similar towing experience with the '96 dually I have my eye on, especially with the wider stance and stability of the rear axle and a bit longer wheelbase. The Excursion does great hauling the camper, but it ends there. What really attracts me to this dually truck is that I can throw dirty stuff like firewood, bikes, grill, etc. easily in the back of the truck and go while still hauling 3 kids along with us, whereas that's not an option with the Excursion.

My current truck that I recently bought is a 1997 W/T 1500 with a 4.3, auto, and 3.42 gears according to the glove box. We do 95% of our camping within 20 miles of our house, so it's all short trips on country 2 lane highways. I'm tempted to try hauling the camper with it in 3rd gear about 50 mph, but I know it will be way overloaded. I do see OBS Chevy's hauling old heavy campers to the campground though, so I know it can be done! My friends and I have owned many OBS 1/2 ton trucks in the past and they've hauled much more than they should have!

Go ahead and tell me I'm an idiot for even thinking about hauling the camper with my '97 1500 so I get that idea out of my head right now!

Well, I guess you could tow your camper with your '97....with some 4.56 gears! Imagine the face of the F250 owners, LOL.


FWIW, the current generation Express 2500/3500 have the 4.3 as a base engine! I know it's an EcoTec/gen V, but still.

 

[andy396]

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I'm not sure which V10 this is referring to, I'm guessing the Dodge V10, but I came across this a while ago while googling one night and I've never been able to find it again. So since we're on the topic here's at least a nice reference of the 7.4L L29 Vortec torque and horsepower dyno curve.

Oh, and yes you're crazy to pull 9000lbs with your 1500. Don't do that, use the dually.

 

[8T7K5]

I'm in the process of rebuilding/reconditioning a 454 in my 96 K2500 Suburban. It's got 196k on it and apparently had a very rough life before I bought it. Mine had a miss, which was remedied by replacing the ignition coil and ignition control module. I'm about to replace the injectors with some Bosch units. Fuel pump/filter/regulator have also been replaced. I've done quite a bit of research and the stock injectors are problematic so if yours still has them, they most likely need to be taken out. My oil has a strong gas smell which I suspect is because of the injectors leaking.

I've driven mine probably less than 2 miles since I bought it last summer so I can't comment on mileage. It was in terrible condition but is slowly coming back to life. Weather permitting, it'll get a new cam, timing cover, upper and lower intake gaskets, distributor, and injectors. Keep us posted on your progress.

 

[454cid]

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I'm not sure which V10 this is referring to, I'm guessing the Dodge V10..

The Dodge was bigger, like 488ci and the Ford is smaller.

 

[1-8-4-3-6-5-7-2]

The Ford is a 6.8 415 cu in

Could the 455 in the diagram have been made by GM? https://www.google.com/amp/s/gmauth...-engine-discovered-and-its-being-rebuilt/amp/

 

[1-8-4-3-6-5-7-2]

Would a 96 Vortec 4.3 possibly suffer from the leaking injectors as well?

 

[stutaeng]

Would a 96 Vortec 4.3 possibly suffer from the leaking injectors as well?

Yes, but the 4.3 Vortec, along with the 5.7 Vortec has the infamous "spider injectors." They are under the intake plenum. My DD is a '99 Silverado NBS ECSB with 256k miles. It has developed an intermittent miss and I suspect it may be the injectors. They are the original. I'm not complaining with so many miles on it. I did the intake manifold gasket leak replacement just last year, but didn't mess with the upper plenum. Just haven't had time to diagnose it.

The outboard injectors like the 7.4, 8.1 and Gen III LS+ are much a much better design.

 

[Christian Steffen]

If you do buy this truck, i 100% recommend a tune and better exhaust. The stock tunes really suck.

 

[1-8-4-3-6-5-7-2]

Yes, but the 4.3 Vortec, along with the 5.7 Vortec has the infamous "spider injectors." They are under the intake plenum. My DD is a '99 Silverado NBS ECSB with 256k miles. It has developed an intermittent miss and I suspect it may be the injectors. They are the original. I'm not complaining with so many miles on it. I did the intake manifold gasket leak replacement just last year, but didn't mess with the upper plenum. Just haven't had time to diagnose it.

The outboard injectors like the 7.4, 8.1 and Gen III LS+ are much a much better design.

Thanks for the info! I'm getting old and so is my memory, but I'm almost certain I replaced the spider injectors in my 1996 Suburban a long time ago.

The 4.3 in my current (new to me) truck run goods and is smooth, but the power seems to surge a bit as I accelerate. It's not bad enough to affect the driveability of the truck and I really doubt most people would notice, but I'm one of those guys who is real particular about having an engine run the best it can. I'll start with a fuel filter and new plugs, wires, cap, and rotor.

 

[1-8-4-3-6-5-7-2]

If you do buy this truck, i 100% recommend a tune and better exhaust. The stock tunes really suck.

Who does good tunes nowadays? Are mail order tunes where I send in the computer and get it back still a thing?

Years ago on my '96 Suburban the exhaust pipe kept cracking near where it bolts to the passenger side manifold. The guy in the exhaust shop said it was because the A/C drain dripped on it. Instead of replacing it with the pipe with cats in it I went with this instead https://www.jegs.com/i/JEGS/555/310...MInqvu18X_5wIVEMZkCh1Z1QjeEAQYASABEgKF0vD_BwE and got a Black Bear tune IIRC. I didn't go wild with the tune, but did have the rear O2 sensors turned off, top speed limiter removed, speedometer corrected, and possibly shift points altered.

Otherwise yeah, I'd love to go look at the dually for sale. The problem is that it's a 2 hour drive 1 way to see it and I've called the dealer 3 times with no answer, left a message asking them to return my call, and sent them an email 4 days ago that remains unanswered as well. I'm not about to make a 4 hour trip to go see a truck that may have been sold already or is a hunk of junk or the dealer is closed for the day, which brings me to my next question below...

Please provide your honest opinion of this truck based on the info and pics in the ad https://www.carsforsale.com/used-ca...decatur-il-d367361/inventory/details/62952469