Anyone use a 5.3L for towing?

[Russell]

Hey guys!

I've got a possible line on a low milage 5.3L V8 from a 2000 Chevy 1/2 ton that a buddy of mine totalled a while back. I was reading, and it seems those engines are good for 285 horse, and about 320 ft lbs of torque in 2000.

I want to put this into my K25 to replace the TPI engine, infront of an NV4500 / NP241. The truck has 33" tires, and 4.10 gears.

Do you think that this thing would have enough power to be useful in a tow vehicle, or should I be saving my pennies for a 6.0L?

The largest load I'd be towing would be up to 8 quads (two on a sled deck, 6 on a trailer) or a 22 foot camper, whichever is heavier. I'd also be hauling water with it (1000 gallons at a time, on a 2500 lb trailer), and hauling my K5 to wheeling spots.

 

[Pookster]

more power than any stock TBI 350. Try to find a dyno sheet for that motor, see if your cruise speed and rpm match up well... I dont see a problem.. Its at least 30% more powerful...

 

[jekquistk5]

it can be done with a 5.3, but I would go 6.0 if you can find one.

 

[Russell]

6.0Ls are typically twice the cost, for not a whole lot more power output... Also horrible on gas, my father averages 13 mpg, and drives that thing slower than most grannies, lol

The 5.3L in our tahoe is really nice, seems to have lots of power, and gets pretty reasonable mileage too, as high as 20 mpg highway, and around 14 - 15 city...

 

[guz71]

I had a z71 tahoe with 4.56's and 35 with the 5.3 and it pulled pretty nicely. It defiantely did a lot better with the lower gears vs. when it was stock and 3.73....that motor like sbe wound up a bit more. While the 6.0 doesnt have a whole lot more power out of the box, it can be pushed a lot harder than the 5.3. Unless you want to rebuild it with forged internals, exhaust, tune, and intake are all you really want to do with the 5.3. With that setup i was getting 11-12 in town and 14-15 on the highway. With a 3000 pound trailor i was getting high 13's on the highway. I had a tune and exhaust and 0-60 it stomped most chipped diesels.

 

[Russell]

well, we'll see what the cost winds up being, and maybe I'll be listing a TPI setup to offset the cost a bit.

There is definitely a huge attraction for me in not having to do any major tuning to the thing... Just getting it flashed with a prom for a standard transmission, and getting rid of the VATS... I'll probally run most of the emissions systems just cause, and my truck is already rigged for the high pressure fuel system....

Does anyone know if the stock exhaust might be something I can patch together on my K25? I know that our truck have the driveshafts drop on the opposite side, but it'd be nice to have all the cats and mufflers etc all there already...

 

[Hogback Fabrication]

(1000 gallons at a time, on a 2500 lb trailer), and hauling my K5 to wheeling spots.

What kind of truck is this going in with what brakes? You are probably talking about ~11000 pounds there, which is probably a fair amount more than any 1/2 ton is capable of.

 

[Russell]

Talking about my GMC.

Its a 3/4 ton frame, and front diff, but I used 1 ton springs out back with a 14 bolt FF with big HD brake drums on it. I'm running a hydro brake booster to boot. I'll eventually get the D60, and 1 ton rated springs up front as well.

Trailer the water tank sits on is rated for 10 000 lbs, and has brakes on both axles. And no, I won't be towing both a load of water, and the K5 at the same time, lol

 

[resurrected_jimmy]

I have used a 1/2 ton sub with a 5.3 and was actually quite pleased with how it towed.

 

[RedDevil]

I had an 00 Z71 w/ the 5.3 and used to tow 5000lbs+ regularly, no problems at all. It pulled very nice on the highway, plenty of power. I just took it easy when it came to hills and such but besides thats, it would go along good.

 

[JEBSR]

Towed my blazer on an all steel 18 ft trailer from TN to FL with not troubles. I was able to run it at any speed I wanted and pulled great. When going up larger grades in TN I had to use 3rd only but everywhere else I was able to use OD.

My truck (my wifes truck actually) is an 03 Avalanche (6800#s on the scales) 5.3 and a 4L60E with 373's and locking diff. my trailer weighs around 1400, and I'm not sure about the Blazer but I would guess 5-5800.

 

[gmc4cw]

6.0Ls are typically twice the cost, for not a whole lot more power output... Also horrible on gas, my father averages 13 mpg, and drives that thing slower than most grannies, lol

The 5.3L in our tahoe is really nice, seems to have lots of power, and gets pretty reasonable mileage too, as high as 20 mpg highway, and around 14 - 15 city...

both situations are because of gear ratios. the 6.0's are always paired up with 4.10 where the 5.3's had 3.73 or 3.42's unless someone special ordered the 4.10's.

the factory ratings are conservative. with a good exhaust and intake and a reprogram that will make plenty of power for what you want to use it for.

 

[Russell]

Both the 2500HD, and the Tahoe have 4.10s. The Tahoe does have bigger tires though... Both tend to run about 2200 rpm at 100 km/h, and while the 6.0L is definitely a tank, and moves pretty good, I'd say the Tahoe isn't that far behind...

That, and the 5.3L is available to me right now, while I don't have a 6.0L available to me.

I think I'll put the 5.3L in, and see how it feels with the 5 speed, 4.10s, and 33" tires, if it feels like it is working too hard, I guess I can find a 6.0L, and sell the 5.3L to help offset the cost...

 

[bowtiepower00]

I'd jump on the 5.3 if you can get a deal on it. The 5.3 has much more power than any earlier factory SBC, period. Drop it in, add a programmer and intake, and let it run. When unloaded, you'll get better mileage, too. The difference is in the gearing, as mentioned before. With the NV4500, that 5.3 will scream. You could always change the cam, get the heads worked, or add a blower later if you need more power.

 

[Russell]

Yeah, I'm working the deal out, it'll involve loosing the K5, but I think it is worth it