[ho428]

All things equal, Carbed or injected, modern ignition, iron exhaust manifolds, PS, PB AC, AT. In a 10,000 lb rig pulling 8000 lbs of trailer.

Which would be the better tow engine and why?
455 Pontiac
454 Chevy
460 Ford

[Skip Fix]

All I can tell you is in my wife's old 1/2 ton 454 truck with carb,headers it got about 7mpg pulling a horse trailer. Kind of scarey with a 20 gallon tank! Didn't know the trailer was back there though,probably as fast as my 78 TA with the factory 180 hp motor too.

[Z Code 400]

Good question....

My choice would be the engine with the longest stroke....Robert

[PLAY400]

My old supercab camper special had a carb'd 460. Hook up, set the cruise and go. Remember 1 trip we all headed for home at the same time and were to meet at my place when we got to town because I was on the outskirts. Well we were home, parked, unloaded and having a couple before the 1 buddy showed up. Rest trickled in over the next 1/2 hour. Apparently there was quite a headwind we didn't notice although we did go thru a lot of fuel. My MH has a 440 which is a dog compared to the 460

[David Holmberg]

I've run dozens of Sim's on my Perf Trends Pro analyzer and all three can do it.
But the Pontiac will make the most TQ, lower than the other two, in most cases.

When Chevy went to the 8.1 from the 7.4 they added stroke, and the 8.1 is a Beast!

Install a cam with 208/215 numbers @ .050 on a 114 and you'll make a ton of TQ in the low to mid 2K range, right where you'll be towing. (The more duration you add the higher the peak TQ will be, and not much higher overall in a towing setup)

But I'll finish with this, Real trucks that tow, don't have spark plugs.

[BigCat4spd]

"But I'll finish with this, Real trucks that tow, don't have spark plugs. "

A buddy of mine bought a Dodge Power Wagon 4WD with the Cummins Turbo Diesel when it came out. He had great big, tall wheels/tires on it and it was truly a bad a$$ looking truck. It jumped out at you.

After seeing it for the first time, I said, "Tommy, what in the heck do you tow with that truck?" He looked at me, rubbed his beard and in his slow, soft southern drawl said, "Anything I want to." 'Nuff said. He nailed it.

My experience with carbureted, gas powered tow vehicles is lousy mileage. Period. I'd go for real FI, any time, as long as the engine was a long stroke, high torque engine. Don't even think about something along the SBC line. It won't work.

[mechanic17]

Not trying to make a jackass claim here, but don't ever underestimate a SBC of any displacement. I once had a 1/2 ton stepside with a 283 w/ fuelie heads 4 spd., and had to tow a VERY heavy trailered load from Vermont (up and down steep hills) to Rhode Island, and just felt sure I'd never make it. Well, no problem. From then on I have always called that vehicle "the little truck that could." What they lack in brute strength, they make up for in perseverance.

[67bonnie455]

The 455 Olds with a 4.25" stroke and the 455 Pontiac with the 4.21" stroke are the best. In my home town, one of the contractors actually put a 455 Pontiac in his dump truck because he got tired of replacing 454s (back in the gas semi days). Worked much better that the Chevy and lasted longer. He also did it with a school bus. He was a GTO guy. These long stroke motors make 550-560 ft pounds of torque. Diesels make 500-600 as a comparison.

Go with high flow cast iron exhaust manifolds, and a mild cam with a WIDE LSA. (I would definately put the 068 Pontiac grind in it). It will tow very well, but hard on gas compared to a diesel, but better than the shorter stroke 460 and 454. The F350 with a 460 and a 4 spd like to get about 8 mpg. The 3.90" stroke motor revs high in 4th gear. You turn a 454-460 cube motor at 3000 rpms going down the hiway, a lot of fuel is goint through it!

My little 5.3 no torque monster gets 10-11 towing my 27' camper turning 2700rpms. Our motor home with 400 Chevy gets 6-7 mph When I am towing, I wish both of them had 455 in them.

[mechanic17]

Oh, not to mention you can go 4" stroke and 4 1/8" bore in 'em nowadays. Cheaper than a 455, too, or probably any big block for that matter.

[rod cole]

Cheap and not on you're list 500 caddy. BB chevy in the day all used oil no matter what you did. I have never been underpowered for towing sometimes you just have to slow down. Currently use a 97 suburban with a 350 when I picked up my Tempest in Las Vegas gas was high and started out at 70 to 75 got 9 miles to gallon slowed down to 60 and got 14 needless to say trip took a little longer. I even have pulled weighting 12000 pounds with a 350 olds deisel not recommended but can do it. Rod

[67bonnie455]

The big Caddy would yahn towing down the road. As a matter of "theory" for the best motor, I think the 525 Caddy would have to be the best. Thanks for pointing that out!

Any heavy duty motor that will take the heat with the correct gears will work, such as the 350 truck motors. But the question was theoretical.

[PunchT37]

455 Pontiac. And you can do it with that big cast crank without having to use a forged for heavy pulling. Small port heads are a plus also.

[the-rookie]

my If your going to be towing a lot, and considering your combined weight any of those three would be a good choice. Do your self a favor though and put a Gear Vendors Overdrive unit in the rig. There's nothing like having a overdrive for every gear when towing, or not towing for that mater. You could run any of those engines in stock form out pull a high hp high tq engine. There would be no lag when up shifting as the engine will always be in its sweet spot. You'll get better gas milage and you'll be able to pass instead of being passed. Don't spend all your cash on the engine, same some for a GV OD unit, you'll be glad you did.

[lust4speed]

I had a 454 in a 34' Pace Arrow and sold it to a friend when I purchased a 34' Bounder with the 460. Shouldn't have sold it to a friend we travel with -- he leaves me in the dust up the grades if we are towing equal weight car trailers. I have to be 1,000 lighter to maintain the same speed as the carbureted Chevy.

Here are some grade speeds from different units I have owned going up the mountain on Hwy 138 to LACR before they closed down:

1980 SBC 400 Suburban hot rod 51 MPH at crest, and 7.5 MPG towing

1990 SBC 350 Suburban FI 38 MPH at crest, and 10 MPG towing

1997 BBC 454 Suburban FI 56 MPH at crest, and 11 MPG towing

2003 SBC 5.7 Avalanche FI 67 MPH at crest, and 12.5 MPG towing

2008 Duramax/Allison Don't know, they closed the track before I got the truck, but it halls a$$.

The Avalanche has the shift points altered but still on an 87 octane program. It cleared the top screaming in 2nd gear, but still had a few MPH before upshifting. When we towed using the Av and 2500 to Pontiac Heaven last year, the 2500 was only 3 MPG better 16.5 vs. 13.5 going, and 13 vs. 10 fighting a severe headwind coming home. The Avalanche definitely knows the weight is there, but does a great job. The Duramax has no idea that the trailer is back there, and if caught behind a truck, it can pull out and get up to speed in no time. The Avalanche (and all previous tow vehicles) was cooked if it got trapped and lost speed.

[Skip Fix]

Mick 5.7 ?, I thought the Avalanche either had a 5.3 or a 6.0 in them. My wife's 2002 5.3 has a pretty flat torque curve and pulls the horse pretty easily,not as easy as the old 454.

[Cliff R]

The Pontiac engine has a slight advantage of the three mentioned due to the small size of the ports in the cylinder heads. This keeps velocity up and enhances low speed torque, all else being equal.

I've had to opportunity to build 454 BBC's, 460 Fords, 350/400 SBC's and 455 Pontiac specifically for towing applications. The 460 Ford has a very strong bottom end, stout rods and a relatively short stroke for the CID. The 454 Chevy has always been a decent truck engine with the smaller peanut port heads, but is not all that efficient (high fuel consumption). The Pontiac 455 with it's long stroke and long rods, always fair quite well for towing in nearly any configuration.

All in all we've been successful with all of these engines, as they were custom built specifically for towing, so we could match the engine power curves to the weight, gearing, etc.

One of the very best towing engines we every built was actually a 360 Mopar engine, and pound for pound it really delivered everyplace, even as well as or even better than some of the larger engines we've set up to do a similiar amount of work. Set into a late 80's 3/4 ton truck, there isn't anything it couldn't do as far as towing is concerned. With 4.10 gearing it was a BEAST everyplace. For the engine build I used a later block with a hydraulic roller set-up, well prepared late style heads, and dual plane intake/q-jet.

Built a few 350 SBC's as well, and they towed very well. My dad had a 91 2WD 3/4 ton with 3.73's and NV4500 transmission. I built an early 90's roller 355 for it, with flat top pistons, swirl port Vortec heads, and custom HR camshaft. He fequently towed a 6400lb trailer with 4 mules and all their tac in it. Behind that, another trailer with his covered wagon on it. It did a fine job with it, and no one could believe he successfully pulled that much weight with a small block 350 engine.

Folks automatically think that long stroke engines offer significant advantages as towing engines. This is true to a point, but the longer stroke simply makes them want to produce their torque earlier in the rpm range.

A well set up 454 BBC, for example, is a real brute for towing, but it's going to want and like more gearing than a very similiar Pontiac 455 in the same application. Set up to spin around 3000rpms at the desired towing speed, a 454 isn't easily pulled out of it's power range by any amount of load.

Also keep in mind, that gas engines in towing applications, much like diesel engines, like manual transmissions. Automatic transmissions "suck" a lot of power away from the engine, even with TCC's. The parasitic loss, driving an oil pump, etc, robs considerably more power from them than a manual transmission. Typically, unless you have a Duramax with a 5 or 6 speed Allison, the gearing on the automatics isn't as well spread out as the 5 and 6 speed manual transmissions.......Cliff

[Scott M]

Funny you mention towing.

I'm thinking about using a 4.75" or longer forging from Ohio crank in a 389 block to drop into a '76 Grand Safari with a Class IV.

If that works, the '61 Catalina wagon will get one....with a 3.90 rear gear.

[lust4speed]

Originally Posted by Skip Fix

Mick 5.7 ?, I thought the Avalanche either had a 5.3 or a 6.0 in them. My wife's 2002 5.3 has a pretty flat torque curve and pulls the horse pretty easily,not as easy as the old 454.

Whoops, bad coordination between brain and fingers - definitely 5.3 I've found that if you don't mind letting the trans and engine work their hearts out, the 5.3 definitely gets the job done. My wife's 2002 Yukon XL gets better mileage than the Avalanche (probably because of near stock tires compared to the 35's and 4.56's in the Av), but it also is a little milder in performance with no programmer.

Also had an old short Winnebago motorhome with the 440 Mopar in it, 5.5 or less MPG not towing, and I think we dropped down to 4 MPG with just a trailer full of bikes behind it.

[madokie]

i second the 500 caddy,several salvage yard operators i know, use it because the 454 is worth more to sell and has no avantage over a 460 or the 500 caddy ,both of which are still plentifull in our junkyards .also they say the 500 lasts longer ,it has bigger bearings than the other 2,and uses less gas.

[gtoroadracer]

I appoligize if this has been mentioned and I am repeating myself but I would have to go with the 454 chevy motor if those are the three choices. 1st for the obivious reason you do not want a Ford taking a Pontiac to a race, kinda like cross bredding it just does not happen. Keep it in the family use a GM engine. LOL So that will leave either the Pontiac or the Chevy, now for the real reason, towing requires more demand on the motor at certain rpm ranges. We all have been towing up a hill and it seems like it will take forever for the truck to get up a hill and you keep an eye on the tach and it is just staying at 4,000 rpm for what it seem like an hour. Well while that motor is turning those RPM the load that is being put on the crank is way more than any car will ever see. So break it down this way 455 Pontiac 3.25 mains versus 454 with 2.75 mains. The 2.75 mains will be able to handle the heat better due to a smaller rotating surface. So while the Pontiac will defeniately get the job done, I am looking at the longevity of the question and I would say go with the Chevy. I would have to agree with David, when it comes to towing you can not beat a diesel, but my 8.1 chevy does pull very well.