Any body have experience with both of these motors. I am trying to decide between the two for pulling my trailer. I pull about 5000 miles a year. I live in Utah so there are plenty of mountain passes. Trailer is an enclosed trailer weighing about 5000lbs loaded. Thanks for any input.

8.1L is defenitely supierior....But not alot. Its pretty much the same block for them both. Ive felt some strong 7.4L's but Im pretty sure the 8.1L has a little more. You would prob be happy with either. But Im partial to the Allison behind the 8100 in the pickups so I like it better.

I have a 98 454/4L80E in my dually. I also have done many upgrades to it that has helped out towing on many levels. The biggest thing is the entire exhaust on the 454's isn;t the greatest. I have Doug Thorley Tri-ys full length headers high flow magnaflow cats and a flowmaster cat back. I also have a custom PCM tune.

I have no experience with the 496 however there isn't much aftermarket support whereas the aftermarket support on the 454 is much much better. These older vortec trucks aren't are getting harder to find in good condition however they are very good performers once some of the short comings are changed out or fixed as I stated above. Fuel consumption on both is about the same from what I yield and what I see others get with an 496.

Either should work towing 5000lbs. I had a 97 Vortec 454 and it was fun but it didn't tow that well. I was towing a 24' trailer with a vehicle on it or a loaded cattle trailer weighing 18K or better.

I had a 99 CCLB 4X4 454 with a pcm4less tune, 3" exhaust, and a cold air intake and I wasn't impressed with it pulling my 10K lb toyhauler up Parleys & Sardine Canyon. My buddy loves his 8.1. I recommend the 8.1/Allison and a programmer that you can use to remove some of the torque management. Good luck!!!

And by the way, on a daily basis, my buddy beats the hell out of his 100,000 mile whipple supercharged intercooled 8.1/Allison. I'm convinced that the 8.1 is bullet proof.

The 8.1 should have a little more power but with the Allison tranny i am sure it will get far better gas milage towing.

we use to have a 98 GMC cc/lb with a 4" lift on 35s w/ the 454 and whipple supercharger. that bad boy would pull out 18k fifth wheel up 6% grades at 75 mph all day long without issue. Truck had 10k when the charger went on and my dad was parinod of the trans giving issues so at 70k, we sold it. Plus the dmax came out by then and he had to have one

And by the way, on a daily basis, my buddy beats the hell out of his 100,000 mile whipple supercharged intercooled 8.1/Allison. I'm convinced that the 8.1 is bullet proof.

Thanks for the input! How does your buddys 8.1 witht the whipple compair to your lb7? Would your 454 mantain highway speed up parlies canyon with 10,000lbs or did it slow it down quite a bit?

Repairs and maintainence are much easier on the 8.1. You could change the plugs, wires, injectors, regulator, and EGR valve in the time it would take you to change the cap and wires on the 7.4.

Vernon

Repairs and maintainence are much easier on the 8.1. You could change the plugs, wires, injectors, regulator, and EGR valve in the time it would take you to change the cap and wires on the 7.4.

Vernon

x2. coil-on-plug ignition > distributor ignition

If you only pulling the 5,000lbs 5,000 miles a year just get a half ton with the 5.3 and add some airbags and it will do fine.

Any body have experience with both of these motors. I am trying to decide between the two for pulling my trailer. I pull about 5000 miles a year. I live in Utah so there are plenty of mountain passes. Trailer is an enclosed trailer weighing about 5000lbs loaded. Thanks for any input.

i've had to drive both, towing extensively, and the old adage that there is no replacement for displacement does hold true to a certain extent. I would lean toward the 8.1L since it sounds like you will probably be pulling some grades. Does the 8.1L you are looking at include the Eaton rear locker option?

If you only pulling the 5,000lbs 5,000 miles a year just get a half ton with the 5.3 and add some airbags and it will do fine.
May be in the flat lands but it will be slow going with the 5.3 up steep grades at 5000 to 10000 feet. I just sold a 6.0 because I wanted more power for pulling and I currently have a 5.3.

Any body have experience with both of these motors. I am trying to decide between the two for pulling my trailer. I pull about 5000 miles a year. I live in Utah so there are plenty of mountain passes. Trailer is an enclosed trailer weighing about 5000lbs loaded. Thanks for any input.

What year is the truck and what regs do you have to comply with? I have an 85 CC dually that I just built a 489" for. It should do the job, behind it is a 4spd, GV OD, 4.56 gear

i've had to drive both, towing extensively, and the old adage that there is no replacement for displacement does hold true to a certain extent. I would lean toward the 8.1L since it sounds like you will probably be pulling some grades. Does the 8.1L you are looking at include the Eaton rear locker option?
I dont know if it has the locker option. Where can I look to tell if it has it?

i think its a g80 code on your vin?

RPO G80, look in the glove box on the data sticker

I have both side by side in my garage. The 8.1 pulls much stronger but has the allison vs. the 4L80E, diff's are bigger as well as the frame. Hard to compare the two trucks when everything is different. 8.1 is harder on fuel but doesn't go through injectors like the 7.4L. All comes down to finding a well looked after truck that you will be happy with. Either will pull 5000 lbs nicely. my 7.4L pulls our sled trailer nicely (approx 7500 lbs loaded), put I wouldnt use it to pull or 12,000 lb 5th wheel. Keep in mind the 6.0L was meant to replace the 7.4L

They are both great trucks with great motors/trannys. I would be open to either of them and just get the one with milage/maintenance/price that you like. And the distributor on the 7.4 is not nearly as bad as people make it out to be you can do it without removing the upper intake plenum in less than half an hour if you know what your doin. Good luck with your truck shopping and have some fun with it.