C3500 diesel vs 454… towing

[BNielsen]

I know whenever I see another 400 on the interstate/freeway pulling a trailer, it's usually a CCLB dually pulling a comically large camper or a large, enclosed 5th wheel car trailer. And they're keeping up if not passing other vehicles.

Which agitates me some considering my truck will pull well to a certain point, and then it can't get out of it's own way. 96 454, bone stock aside from an 0411 and a true-dual exhaust. It'll pull my 7500 pound camper no problem at 65/70, but then something happens. It starts misfiring and I can barely manage 40. Still chasing that down. But when the truck is running right it's more than capable of handling anything I want to do, hell there was some hills between my place in NC and the beach in SC that my truck just ate up and kept up with my friend's tuned LML Duramax. @Supercharged111 is right on the money, a tune and exhaust are two of the best things you can do for relatively cheap.

Take a look around this thread; ever since the loss of the big 454 thread on FSC it's been a bit of digging and scratching to build back up a database of sorts. Might help you reach a decision. Personally, I've got plans to build the 454 to around 400 horse in my 96 K2500 for local trips/local pulling, but my 2000 K3500 with a 6.5L will eventually get a 450/500 horse 12-Valve for longer trips.
Vortec 454 Thread

 

[Schurkey]

A diesel without a turbocharger is a gutless piece of crap. GM, Mercedes, doesn't matter who made it. No turbo = junk.

The 6.2 and 6.5 were recognized as turds about three minutes after the Duramax was released. Even the turbo 6.5 had nothing on the Max.

Diesel fuel used to cost less than gasoline. No idea why that changed, but I'll blame the sulfur reduction/EPA until I find out a better reason.

I've got experience fixing gasoline engines, and gasoline fuel systems--carbs and injection. None fixing Diesels. That pretty-much seals my decision.

The HT502 is interesting...and expensive. On the plus side, the GM warranty should be pretty good. Stroker 454s are becoming outright common. That'd probably be my first choice.

 

[RedneckWithPaychecks]

I have a 1989 Chevy K2500 454. I have a 27’ travel trailer that I used to tow often. It’ll tow it like nothing. It’ll be towing said travel trailer tomorrow to put it back in storage.
I’m lazy so I haven’t done tunes for it, at least the engine kind. Again, an exhaust is needed. Mine is 3 inch straight pipes without cats into a Harley Davidson motorcycle muffler. I did a cold air intake, doesn’t really make a difference.
It’ll pull anything I put behind it.
I have an aftermarket transmission cooler, I’m afraid to see how bad it is but it works. The cooking on mine is good enough. It’ll be at the “I’ll be a little more careful” level. It reminds me to not drive it fast with trailers. When I don’t have trailers, it’ll burn tires until they blow.

I haven’t driven a diesel. But I can bet it isn’t as good as a 454. I love mine. 430+ thousand miles still running like new. Maybe.

 

[L31MaxExpress]

Low mileage 8.1 swap. Get one from a van or GMT400 3500HD so that the accessories will be in the right place. I used a 3500HD fan shroud and 34x19 radiator with a duramax fan. ZERO cooling issues in my Tahoe. Basically treat it like a DBW 24x swap LS1 except it bolts right on the old 454 motor mounts and bolts right up to the 4L80E. Get a GMT400 3500HD pedal, bolts right on as does the diesel pedal.

 

[TCBRacer77]

See this is why I love this forum lol, so much great advise! Thank you all, I think for sure it sounds like the 454 is the best platform to work with for what I am thinking, how about transmissions? I know it was mentioned a little bit but what options are there? I mean I have the notion that To a point it doesn’t matter what kind of power you have or weight you can pull if you don’t have a decent transmission, also breaks lol. Will an Allison trans bolt in with a 454? Is that even worth the trouble of creating clearances?

 

[94K3500PROJECT]

So, with the way things have been looking the past several years, I’m starting to lean towards a C3500 454 4x4 truck for a future build, and slowly starting to dislike the idea of a duramax swap or even a stock 6.5 diesel truck. A big reason is for the price of diesel sky-rocketing as well as the common consensus that the 454s were awesome if you didn’t mind the gas mileage. I would like to have one of these trucks simply for towing a race car trailer, not frequent use and definitely not a daily. Keeping it put away and keeping miles off of it. I was also looking at Chevrolet performance HT502 crate engine and wondered if it would be an easy drop in to a tired 454 truck?

Just curious what you guys think if a diesel is worth the hype if the 454 is sufficient? Even compared to a duramax swap??

As with ANY gas engine used in this manner displacement and intake runner design will trump about anything else as far as importance.
Cam selection is very important too but not because you’ll gain much for this application but because you can lose a bunch

The other performance advantage is in gearing and transmission swaps. I’m not sure I’d spend the money on the swap but the NV5600 manual really shores up the gear spacing issues on an NV4500.
IDK that may be something I look into even.

I agree that if I could eat the fuel costs I’d go 454 over everything else

 

[618 Syndicate]

Stick with a 4L80 if you're going with an auto. The extra overdrive of a 6L isn't significant enough to warrant the expense or hassle of the swap imo.

 

[94K3500PROJECT]

A 6l90 isn’t just an extra overdrive.
Gearing splits are much better, much lower first and more OD for more fuel mileage in 6th

It would be a very expensive swap though

 

[TCBRacer77]

As with ANY gas engine used in this manner displacement and intake runner design will trump about anything else as far as importance.
Cam selection is very important too but not because you’ll gain much for this application but because you can lose a bunch

The other performance advantage is in gearing and transmission swaps. I’m not sure I’d spend the money on the swap but the NV5600 manual really shores up the gear spacing issues on an NV4500.
IDK that may be something I look into even.

I agree that if I could eat the fuel costs I’d go 454 over everything else

I wasn’t very experienced towing with a manual trans before I swapped my 97 c1500 with an nv3500, then towed a trailer containing our entire life from CA to AL lol, so now I am actually surprised how much better I like towing with a manual trans. However, in the case of camping or racing, I think I still might prefer the ease of an auto trans. So honestly the cost of a 6l90 might still be considered if it is in fact worth it. I would rather spend the time and money if that trans would be sufficient and stand the rest of time with no hassle

 

[618 Syndicate]

I wasn’t very experienced towing with a manual trans before I swapped my 97 c1500 with an nv3500, then towed a trailer containing our entire life from CA to AL lol, so now I am actually surprised how much better I like towing with a manual trans. However, in the case of camping or racing, I think I still might prefer the ease of an auto trans. So honestly the cost of a 6l90 might still be considered if it is in fact worth it. I would rather spend the time and money if that trans would be sufficient and stand the rest of time with no hassle

Neither a 6L80 or 90 are worth the expense imo. You gain an extra overdrive that drops highway (70 mph) rpm less than 300. You could take advantage of the deeper first gear by swapping your rear end gears to numerically smaller, but that's an extra expense.
If you could catch an ambulance Duramax/6L90 drop in I'd say go for it, but other than that a 454/496/502 with a 4L80 will meet your needs and be easier.