97 3500 dually engine swap

[Rusty c]

Just bought a 97 3500 dually that originally had a 7.4 that was taken out I have a 5.7 out of a 98 or a 8.1 out of a 02 avalanche that I would like to put in it witch would be the easiest swap to the 5.7 or the 8.1

 

[618 Syndicate]

Level of difficulty depends on what was left behind.
If I were choosing I'd use the 8.1 along with a 0411 swap.

 

[BeXtreme]

Just bought a 97 3500 dually that originally had a 7.4 that was taken out I have a 5.7 out of a 98 or a 8.1 out of a 02 avalanche that I would like to put in it witch would be the easiest swap to the 5.7 or the 8.1

100% agree with syndicate. If you have the wiring harness and computer from the 8.1, that's what I would do.

Nothing sadder than seeing a big old 1 Ton dually limping along with a sad little 5.7 in it.

 

[HotWheelsBurban]

Hey now, don't hate on a 5.7 Vortec in a 1 ton, mine goes plenty good when you get your foot in it. The issue now is with stopping it....
And the small block doesn't want to stop at every other gas station lolol....

 

[BeXtreme]

Hey now, don't hate on a 5.7 Vortec in a 1 ton, mine goes plenty good when you get your foot in it. The issue now is with stopping it....
And the small block doesn't want to stop at every other gas station lolol....

Depends on whether you are towing anything. I bet the 5.7 gets better mileage around town unloaded, and worse mileage towing a heavy load.

 

[HotWheelsBurban]

Probably so! My Burb never tows anything bigger than a 6x12 dual axle uhaul trailer, and the only way you know it's there is on hills, parking or stopping. The smaller 5x8 single axle tows even better. That's what I have towed, earlier this year,the last times I had a big enough show to go to, that I needed a trailer.

 

[L31MaxExpress]

Depends on whether you are towing anything. I bet the 5.7 gets better mileage around town unloaded, and worse mileage towing a heavy load.

My 350 towed well especially once I ditched the 3.73 gear. 12,500 GCVW. Still netted 11-12 mpg on the flats and around 10 in the mountains. I did have tri-y headers and a small cam in it though. With 5.13 gears it would go down the road at 70 mph at 2,800 rpm in overdrive. I was getting ~18 mpg empty with the 5.13s. I put the 3.73 gear back in with the 383 (took about 2 hours to swap the whole rear end). I tow in 3rd at about 2,750 rpm @ 70 now. Running solo its at 2,100 @ 70 and 19+ mpg. With fuel costs being what they are, I slowed down to ~60 mph on my last trip with the travel trailer. Over 700 miles it got nearly 14 mpg. My travel trailer and van have the aerodynamics of a brick and about the drag of hauling an open parachute behind me so slow and steady pays back woth less time spent at the pumps.

 

[GoToGuy]

Probably so! My Burb never tows anything bigger than a 6x12 dual axle uhaul trailer, and the only way you know it's there is on hills, parking or stopping. The smaller 5x8 single axle tows even better. That's what I have towed, earlier this year,the last times I had a big enough show to go to, that I needed a trailer.

You mean two axle trailer, tandem, not duals on single axle right? I'm just trying to imagine your burb towing ....

 

[HotWheelsBurban]

You mean two axle trailer, tandem, not duals on single axle right? I'm just trying to imagine your burb towing ....

Yes the biggest trailer they have, 6x12, double axle. We pulled one, loaded, with the Burb, and also with our '06 Yukon XL Denali,6.0 and 4L65E. I like the smaller one better,5x8, because it's about the same height as the Burb. So less wind drag. Towed one to Austin and back in April, did well on the hills (and we kept the trans in D instead of OD).

 

[L31MaxExpress]

Yes the biggest trailer they have, 6x12, double axle. We pulled one, loaded, with the Burb, and also with our '06 Yukon XL Denali,6.0 and 4L65E. I like the smaller one better,5x8, because it's about the same height as the Burb. So less wind drag. Towed one to Austin and back in April, did well on the hills (and we kept the trans in D instead of OD).

Funny how the taller and wider trailers are like a parchute isn't it? Had a buddy break down on a river trip a few years ago. 4.0L had blown its head gasket and as we later found out had a near 2-piece head option. I pulled this back from New Braunfels. I had 4 people including myself, he had 3 total. The 7 of us rode back in the van. Threw all the camping gear, coolers and the like in the Jeep. The 350/4L85E and 3.73s handled the load in overdrive on I-35. Don't ask how fast I was running, I was badly sun burned and ready to be home. Trailer tracked right behind the van, no swaying, no dipping, van ran down the road like it was not even there.

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