4.3 vortec close to towing capacity.

[Hungoveraviator]

So I have a 97 K1500 WT with a 4.3. Has a new engine and a newly rebuilt 4L60E. From what I have been able to find out it looks like it had a 5k towing capacity from the factory. My plan is to use it to move 1600 miles away primarily and hopefully after the fact be able to escape up into the mountains the weekend. Region I will be in, the elevation change isn't crazy extreme, probably 4k feet to 7.5k most places.

My plan is to convert a 12-14 foot cargo trailer into a camper so I can insulate it well and include only what I think is neccessary for my purposes. The design would incorporate the ability to move things out of the way so it could be a toy hauler. Am in the really early stages, but from what I can tell, it looks like without anything done to it, the trailer would be 2000lbs and a RZR would be 1000lbs. If the total weight ends up being 4500-5000 pounds is it going to be a pain in the ass to work with? Will probably wait on picking up a RZR until I get to my destination.

Another thought too is that I may be able to put the RZR in the bed and buy a smaller trailer if it is prudent to do so. What effect does payload combined with towing have? Being at the early stages, if it makes sense to do things a different way, might as well plan it out.

 

[stutaeng]

I've got a Silverado ECSB with
4.3 1999 model with 3.42 gears. My towing manual states towing capacity is 4,500 lbs. Jumps to 5,000 lbs with 3.73 gears. They are probably close to your truck. You need to know your gear ratio. I only once towed like 2,000 load on that truck. I don't think it would like towing 5,000 # in the mountains.

Since your engine is basically new, I would regear to some 4.10s. That's going get you the most bang for your buck towing, at a higher fuel economy cost, but I would not care...

As far as pin weight, you should be fine. Pin weight would be less than 1000#, well within the capacity of your truck.

 

[stutaeng]

BTW, my 4.3 came with a transmission cooler and P.S. cooler, but no engine oil cooler. Add that to your truck. That's basically what the V8 towing package consists of.

Will you have trailer brake controller setup? I highly recommend that.

 

[stutaeng]

On GMT 800 they have a "tow/haul" mode on the shift lever. What does is that the ECU holds the transmission gear into higher RPM before shifting. I think that's a benefit because it prevents your tranny from hunting for gears in steep inclines. Will probably prevent the transmission from burning up.

Fortunately, there's a mod that allows you to add that function, via the famous "0411" ECU upgrade and a GMT 800 shift lever. Just be careful, the shift lever came with these little tiny yellow wires that tend to break off...mine is currently in that state

Not sure if you can get a tune for the 4.3 with the 4.10s with 0411. I know some of the Express Vans came with 4.3 and perhaps some were equipped with 4.10s, but they had the 4L80e transmission. Maybe someone can chime in on that?

 

[Gibson]

Fill the fuel tank and drive thru a scale to weigh the truck empty.
Subtract that weight from the GVW on the data plate.
Whatever is left is what you have to work with.
A 5K trailer will have ~500>700 lbs on the hitch, so you're not going to have a whole lot of capacity left to put in the bed.
You gotta watch it on 1/2 tons, they don't have a lot of payload.
Engine oil cooler highly recommended.

 

[Hungoveraviator]

With oil coolers mine had one on the old radiator. Lines were leaking like a sieve and everything got milkshaked up. Am actually radiator shopping right now as I don't want to take any chances with the old one. Is there a type that would be best for me to look at with what I will be doing in mind?

 

[SUBURBAN5]

I recommend a v8 radiator. Mine has built in oil cooler and trans cooler. Recommend aux cooler too. It should fit the v6 support just need the v8 hardware. Idk if you can keep the v6 shroud or not. Never tested that since mine already a v8. Saw a video on youtube of this mod

 

[92_Bahama]

I've got a Silverado ECSB with
4.3 1999 model with 3.42 gears. My towing manual states towing capacity is 4,500 lbs. Jumps to 5,000 lbs with 3.73 gears. They are probably close to your truck. You need to know your gear ratio. I only once towed like 2,000 load on that truck. I don't think it would like towing 5,000 # in the mountains.

Since your engine is basically new, I would regear to some 4.10s. That's going get you the most bang for your buck towing, at a higher fuel economy cost, but I would not care...

As far as pin weight, you should be fine. Pin weight would be less than 1000#, well within the capacity of your truck.

This right here!! 4.10 gears will be your best bang for your buck. Add a stacked plate transmission cooler, a finned large capacity transmission pan, transmission temperature gauge, 180 degree thermostat, and an oil temperature gauge. The 4.10 gears should give you the power you need after that the question becomes cooling. You can never have enough gauge/information!!

 

[Supercharged111]

Oil temp? Meh. A tune would help keep the converter locked which will keep the trans cool. Could swap a 4.3 PCM from a newer non-black box PCM S10 as it has loads more features.