How Big a Motor?

[JoelD]

I have a 97 GMC K2500 Ext Cab Longbed with Vortec 350 (275 hp I believe) 4.10 gears and 4L80 automatic. Truck is about 6500 lbs. with me and typical junk in the bed. Plenty of power off the line, but maintaining speed on hills the power just isn't there. I can haul about 9K trailer (14K total) fairly comfortably. Heaviest I hauled out at was 17K total. I'm not in a hurry to do that again. If you plan to fully load that trailer to 14K, you need a bigger truck and more motor. You're going to be rolling 20K. If can afford it, I hear the newer Chevy/GMC with the 8.1 are fantastic. You get the Allison transmission like the diesels which is indestructable. The mileage is no worse than the 6.0 engine. This is a good time to buy trucks, especially "gas guzzlers" like a one ton with the 8.1.

I agree, with weight like that, I'd be looking at a bigger motor than 350.

Another thing to think about is weight distribution and stopping that rig. You need to laod down the truck sum to avoid fishtailing and the like. You're probably going to want 1 ton spring I would think at least.

Final point is legal matters, not sure on that, but I know there are limits out there that can't be legally exceeded.

I haul my load maybe three times per year, if I was in the business and hauling regularly, with the type of load stated above, I'm thinking dually, big block, low gears.

Interested to see how this all plays out.

Sincerely,
Joel

 

[Builder]

I have a 97 GMC K2500 Ext Cab Longbed with Vortec 350 (275 hp I believe) 4.10 gears and 4L80 automatic. Truck is about 6500 lbs. with me and typical junk in the bed. Plenty of power off the line, but maintaining speed on hills the power just isn't there. I can haul about 9K trailer (14K total) fairly comfortably. Heaviest I hauled out at was 17K total. I'm not in a hurry to do that again. If you plan to fully load that trailer to 14K, you need a bigger truck and more motor. You're going to be rolling 20K. If can afford it, I hear the newer Chevy/GMC with the 8.1 are fantastic. You get the Allison transmission like the diesels which is indestructable. The mileage is no worse than the 6.0 engine. This is a good time to buy trucks, especially "gas guzzlers" like a one ton with the 8.1.

I know the kinds of hills you're talking about. If your budget prefers gas over diesel, the 8.1L GM gasser is a torque monster. And like was said above, you get the bonus of an Allison transmission AND another bonus, a G-80 locking rear.

If I wanted a newer truck and couldn't afford a diesel, I'd look for the 8.1/Ally/G-80. It was the absolute best drivetrain combination ever put in a pickup.

The Ford V-10 is a great gas motor, too, but the transmission and rear is not as good as GM's trans & rear axle. Look at the locking rear axle comparisons.

YouTube - 20% grade G80

YouTube - Eaton G80 locking diff

Put an Allison in reverse when you back a trailer compared to the others and you'll see it's more geared-down.

You should also probably be looking for a 1-ton SRW (3500) series truck to make sure you don't overload the rear suspension for tongue weight if you plan to carry heavy cargo in the bed.

Here's a nice truck, but it looks like it might be a manual: http://www.commercialtrucktrader.com/find/listing/photos/print/91420206/

 

[Diamondpilot]

I have a 97 GMC K2500 Ext Cab Longbed with Vortec 350 (275 hp I believe) 4.10 gears and 4L80 automatic. Truck is about 6500 lbs. with me and typical junk in the bed. Plenty of power off the line, but maintaining speed on hills the power just isn't there. I can haul about 9K trailer (14K total) fairly comfortably. Heaviest I hauled out at was 17K total. I'm not in a hurry to do that again. If you plan to fully load that trailer to 14K, you need a bigger truck and more motor. You're going to be rolling 20K. If can afford it, I hear the newer Chevy/GMC with the 8.1 are fantastic. You get the Allison transmission like the diesels which is indestructable. The mileage is no worse than the 6.0 engine. This is a good time to buy trucks, especially "gas guzzlers" like a one ton with the 8.1.

The 8.1 was canned at the end of 2006 or maybe mid 2007. They are forcing you to the diesel. The only real choice in a gas engine for heavy towing is the Ford V10.

Chris

 

[Builder]

The 8.1 was canned at the end of 2006 or maybe mid 2007. They are forcing you to the diesel. The only real choice in a gas engine for heavy towing is the Ford V10.

Chris

I think he's looking for a used gas truck.......

 

[2COR517]

The 8.1 was canned at the end of 2006 or maybe mid 2007. They are forcing you to the diesel. The only real choice in a gas engine for heavy towing is the Ford V10.

Chris

Another brilliant move by GM...... If it ain't broke, change it! Isn't this motor also used in Marine applications in place of the 454?

 

[Builder]

Yep, GM wanted the big $$ from the diesels. The 8.1 with a little refinement could have been a real winner in front of the ally & 11.5" G-80 locker.

 

[wkpoor]

The 8.1 was canned at the end of 2006 or maybe mid 2007. They are forcing you to the diesel. The only real choice in a gas engine for heavy towing is the Ford V10.

I think your right but Mecruiser will have that motor for years to come. My brother bought a new boat 2 yrs ago that was still using the old central port fuel injection that has been gone from the auto fleet for almost 10yrs now. In fact the 454 that supposedly was gone long ago was still available long afterwards.

 

[Diamondpilot]

Most of the boats I sell are 383 stroker motors. You are right though the 5.0 5.7 and the 8.1 are still available. The only problem with the 8.1 and the Ford V-10 is they are gas hogs. My uncle has a 2005 F-350 with a V-10 and the 10 means 10 mpg, the same with the 8.1. Plan on 8 towing.

Chris

 

[Builder]

Why would the Ford V-10 get 20% better fuel mileage?
Just because it's a "Ford"?

 

[Matt_Jr]

The 350's in the 3/4 ton have 20-30 less horsepower then the 350's in the 1/2 ton trucks. Reason is the heavier cranks in the 3/4 ton trucks. The do have the same torque though. I wouldn't get a 350 engine truck to pull a load like that. I've got a 3/4 ton Suburban with a 350 and a 4.10/11 locker and live on a mountain. It struggles pulling my BX24. My 1/2 ton Silverado with a 5.3 will smoke the 5.7 anyday of the week pulling wise. Go diesel or go bigger. You will not be happy with the 350. If you must go with the 350 make sure it's a '96 or newer. They have multiport injection and a little more power.

 

[Diamondpilot]

Why would the Ford V-10 get 20% better fuel mileage?
Just because it's a "Ford"?

That's not what I was trying to say. I was saying see 10 mpg and 8 towing with both motors. My uncles 2005 F-350 with the V-10 is a 4x4 with 4.30 gears so it pulls great but it does not pass many gas stations. I guess he does not care since he owns 3 stations.

I have a friend with a 2006 3500 with the 8.1. Its a crew cab dually 4x4 and he said he has never seen above the high 9's and towing a 5th wheel he got 7.2 last year on his annual trip to Florida. He is retired GM guy, you know about 52, and he takes it easy.

With either truck I would think 10 is a good average. You may be able to squeak out 12 with 3.73's but these trucks need low gears to take advantage of the power band of the big gas engines.

Chris

 

[wkpoor]

With either truck I would think 10 is a good average. You may be able to squeak out 12 with 3.73's but these trucks need low gears to take advantage of the power band of the big gas engines.

I've owned one 454 and its peak torque was at 1600rpm and peak HP was at 2400rpm. It was only rated @ 240HP but when you look at where the power was made it was a towing monster. I had 3:73's behind it.

 

[3RRL]

If you do any amount of towing, especially a lot, I'd reconsider and get the diesel too.
Even though it's more expensive up front, and diesel fuel is more than gas right now, in the long run you'll be much happier. I found my 2008 Chevy 2500HD with Allison gets better mileage towing 7000lbs than my '94 Chevy 350 did running naked. I get around 15mpg towing and the 350 got about 6 to 8 towing and 12mpg naked. The 2500HD get 19 to 20 running naked. It's built to tow and smokes the 350 gas engine. Super comfortable too. Over the years, the extra cost is reduced with some mileage savings. Especially if you're now considering getting a bigger motor. Resale may be another consideration as guys are always looking for a good used diesel.
But the feeling you get knowing you have all this reserve power to tow at decent mileage and relatively little strain on the diesel engine (in comparison) eventually leads to peace of mind.
There is no price tag on the level of satisfaction you get from this.

 

[RobertN]

Hi All,
I am looking to buy a 3/4 ton pickup to pull a 22-25 ft gooseneck trailer rated for up to 14,000LB loads. I found a Chevy 2500. Your opinions, please.

That's a lot of weight for a 3/4 ton. That's 3500 or 4500(350/450 for Ford) with dually kinda weight. That little 350 would be out of it's league, unless you geared with some 4:88's or something.

Even in my Cummins Dodge 3/4 ton heavy duty everything, I would not want to tow that. I could but would not want to.

 

[Treemonkey1000]

If you lived close I would sell you my 1988 Chevy 3500 with a 454 in it. Has the crew cab 4x4 with automatic. Not sure what gears are in it though. Go one ton if you want to have bigger brakes usually as well. Getting going is fine. Stopping is kinda important to.

 

[Builder]

If can afford it, I hear the newer Chevy/GMC with the 8.1 are fantastic. You get the Allison transmission like the diesels which is indestructable.

Man, everytime I say an Allison transmission is indestructable, I get hammered by Dargo.

 

[Diamondpilot]

Man, everytime I say an Allison transmission is indestructable, I get hammered by Dargo.

Nothing is indestructible. My dad always said "if its got T-ts or Tires eventually its going to give you troubles". He has plenty of funny sayings but due to the nature of this site I can not repeat any of them here.

Chris