Would you swap a 454 for 6.0 to pull with?

[Kinghat]

I am approaching the purchase of a 77 crew cab dually. It has a 454/400. Plans are to shorten the bed and frame, go to single wheel, lower it 3/5ish but still keep it 1 ton, and use it to pull with. My question is, would you guys leave the drivetrain alone, or switch to LSx and 4L80E?

Second question, if you found a whole donor truck, would you keep the LSx's stock tank from the donor? I see most everyone use Blazer tanks on their conversions with either in-tank or inline pumps, but wouldn't it be feasible to use the newer trucks tank?

[Kinghat]

by the way, this is the rig.



and this is a photoshop someone did to show my bed length idea

[oldblue1968chevy]

^^those are sweet photoshops! lol

[Critter]

I'm partial to the 6.0/4l80e idea, but it won't be cheap. Are you considering the swap for cool factor or for mileage, or just for the heck of it?

I would probably get the tank, I'm not sure if you could make it work under the truck or not, but it might be nice to get the in tank pump.

[Kinghat]

I was thinking of mileage more than anything.

[Critter]

Well, I am in the middle of a 6.0 swap as well and I can tell you this, the $4,000-$6,000 that this swap will cost you would put A LOT of gas in that 454 that you currently have. You are only going to gain a few mpg from doing this. Now if you are wanting something cool and different, then get after it! That's what I'm trying to do!

[clinebarger]

Originally Posted by Kinghat

I was thinking of mileage more than anything.

If you want mileage while your towing, go diesel. My 5.9 Cummins gets around 20 empty & 15 towing 9000 lbs, These are multible tank averages not that "I get 27 MPG" B.S.

I love LS engines but towing heavy is not its strongest suit. When diesel got really high I borrowed a friends 04 2500HD 6.0/4L80E to haul my travel trailer on vacation......That was a big mistake I averaged 8 MPG. The next year I took my Dodge (same destination) & averaged 16.5.

[ripdog28]

For pulling, 454 no question. With the the 4.00 stroke it is the best bet over the 3.62 for tq.

[Critter]

Originally Posted by clinebarger

If you want mileage while your towing, go diesel. My 5.9 Cummins gets around 20 empty & 15 towing 9000 lbs, These are multible tank averages not that "I get 27 MPG" B.S.

I love LS engines but towing heavy is not its strongest suit. When diesel got really high I borrowed a friends 04 2500HD 6.0/4L80E to haul my travel trailer on vacation......That was a big mistake I averaged 8 MPG. The next year I took my Dodge (same destination) & averaged 16.5.

I agree on all accounts. I'm basing a lot of my thoughts off of a 2004 GMC 6.0/4L80e/4.10 gears that I bought new. I loved that truck, but mileage wasn't a strong point. I got 13 mph on the highway, 9 mpg pulling anything. Maybe you can manipulate the computer, exhaust, etc better than my stock truck was, but I don't see you breaking 16 mpg with the weight of the truck you are working with. Not trying to discourage, just trying to inform. However, I'm sure if you did squeeze 16 mpg out of that rig it would be better than the 454, but not sure by how much.

[mikie 1954]

I have a very good friend that has a new 3/4 ton chevy4x4 that get about 16, 17 mpg by itself. He uses it to pull a 3 horse slant load trailer and it pulls it nicely but won't stay with a 454. I would say it depends on your pocketbook and what your going to pull. Mike

[Critter]

Originally Posted by mikie 1954

I have a very good friend that has a new 3/4 ton chevy4x4 that get about 16, 17 mpg by itself. He uses it to pull a 3 horse slant load trailer and it pulls it nicely but won't stay with a 454. I would say it depends on your pocketbook and what your going to pull. Mike

I'm not sure what you mean by "new" but I'm assuming it's a 2008, 2009 or 2010. That truck assuming it's a gas engine is a 6.2 Liter with a 6L90e transmission (33% overdrive as opposed to the 25% of the 4l80e). To me that truck/drivetrain is a whole 'nother ball of wax and isn't an apples-to-apples comparison with the 6.0/4L80e. Just trying to keep the discussion fair and even.

[rollinhard]

the 6.2 was in cars and suvs not trucks aluminum block. Trucks got the cast iron block 6 litre 07.5 -11

[Critter]

That's right, I had SUVs on my brain I guess. A 2009, 2010 etc 2500 would be a 360hp 6.0 Liter but it would have the 6L90 transmission. Anyway, we got off topic a little...

[lowrollin70gmc]

Possibly put a fast ez efi on the 454 to gain some mileage while pulling. Definitely cheaper than a 6.0 swap and keep the power of the big block.

[mikie 1954]

I wasn't off toppic, the ? Was 6.0 or 454. I still believe that both would be good for pulling but 6.0 will not pull with 454. Agean depends on how much you can spends and how much you pull. You can put any trany you want behind ether motor, just how much you willing to spend.

[KQQL IT]

A 454 seems to get 10 mpg. Had a 86 with a carb and a 4 spd. and a 98 vortec 454 with a automatic and both of them got 10 mpg. pulling or not up hill down hill they got 10 mpg. And no 7.4 vs 6.0 ther is no substitute fur cubes.

[my4by2]

Don't have too much pulling in my projects future, but my '77 had a 454/SM65 in it when I bought it. I am going back with a 6.0L LY6 engine from Mast Motorsports & a GM NV4500 5-speed. The motor made 497hp/463tq on the dyno. Should pull better than the stock 454 would have & get MUCH better fuel mileage too!!!

[slimneverdies]

I remember reading about this and getting advice on this actual topic. I chose to go with a 454 which on paper should give me about 470-485lb-torque after my rebuild and upgrades. My question is does it matter what size your engine is at the same maximum output for torque? Would a 5.3 turbo that puts out close to 600lb of torque be able to pull better than my current 454? I already have a 5.3 built for turbo and it would be an easy swap but I want what would be the best option for my 78 c30 tow pig.


Here's an article that has me thinking
http://www.hotrod.com/how-to/engine/...lock-for-3252/

[Eddie H.]

My daily driver/work truck is a 2500 silverado with 6.0L. loaded with tools and equipment it weighs in at 8300 pounds. The 6 liter pulls it around just fine but the average fuel economy is 10 to 12 mpg.

[Clyde65]

If fuel mileage is your main concern neither will give you better than say 12ish and lower when you tow. The diesel option is the only way to go when towing often and a lot.

You have to weigh how much and how often you will tow as well. Either gas option will tow well but not efficient.

[slimneverdies]

Originally Posted by Clyde65

If fuel mileage is your main concern neither will give you better than say 12ish and lower when you tow. The diesel option is the only way to go when towing often and a lot.

You have to weigh how much and how often you will tow as well. Either gas option will tow well but not efficient.

With these old trucks I'm use to getting 10mpg with the three speed transmissions. I have a well built 4l80e that I'm throwing in the mix so that should help a bit. My real question is can a turbo 5.3 motor with close to 600lbs of torque tow better than a mild built 454 with close to 500lbs of torque? I have both motors available to me so it's one or the other. By the way, I'll be towing a trailer that weighs about 7000lbs at least once a weekend...

[kwmech]

I'm wondering what he did 5 YEARS ago.

['63GENIII]

I was just about to chime in. I always overlook the dates! Lol. I wonder what he did also.

[truckster]

Originally Posted by kwmech

I'm wondering what he did 5 YEARS ago.

He should have some pretty good fuel mileage data by now!

[TJ's Chevy]

6.0 is somewhere's around 366.....A 6.2 is around 379. A 7.7 would be around a 454 or something like that. I'd keep the 454. If its running good...why fix something that's not broken?