Can't decide between 5.3 or 6.0

[71K20chevy]

Originally I wanted to do a 5.3, then a 6.0. Now I want to do a 5.3 again. I will put a cam, headers, and probably 243 heads on either way. Main reason I'm thinking about the 5.3 again is junkyard price, availability, and gas mileage. I don't know if the 6.0 is worth the extra money for 30 extra HP.


Thoughts on this? Thanks!

[Clyde65]

That is a question everyone deals with, it's all up to you.

Is this a daily driver? I think with either the MPG will be pretty
Close and the how I'll be like you said pretty close, the torque might be the only real difference.

[71K20chevy]

Well, when I get my license it'll be my DD for a while until I get a second car. After that though the truck will probably get driven pretty regularly. My dad's got a 99 Silverado with a 5.3, 250k miles, and that thing still gets 19 mpg. My 350 currently gets around 13 mpg, so if I could get 16-17 out of it I'd be happy. I understand that these trucks have the aerodynamics of a brick so they won't quite pull off 20 mpg.

[68GMCCustom]

you only need to go for the 6.0 if your looking for all out power....as in for towing or racing, etc. Oh.....and only 30hp difference? Not in tuned form!

[71K20chevy]

Basically what I'm looking for is something that has good strong power, while still being reliable and getting good MPG. 5.3's and 6.0's get such mixed reviews, that it makes it even harder to pick.

[Robznob11]

well I like the 6.0 because it has the bigger pistons and can run the larger heads if you want to in the future! also any upgrade magnifies with the larger displacement! imo most people cant ever stop adding once they get started, I mean its like you can never get enough. If you buy a 5.3 you put a cap on how far you can go. and lets face it a cam in a 5.3 is awesome but the power in a motor is found in the heads so why limit how big you can go in that area. fyi incase anyone is wondering because the cylinders are smaller you run into valve shrouding problems.

[71K20chevy]

Now I can't decide again Dangit! Does anybody have any MPG numbers for 6.0 4L80E swaps?

[Blackpony]

Keep in mind, you can take a 5.3 and bore it over to run 5.7 pistons and gain a little more bore size. Personally for your situation I'd say go 5.3 with a cam and usual bolt ons and supporting mods with a full custom tune.

[slowcpe]

I'm in the same boat. Started out with a 5.3, then 6.0. I'm now back to a 5.3 to get the swap done and truck on the road. Then I plan to build a 402. For the price to buy a jy 6.0 and mod, it's not much more to build a new stroker assuming you have all the little nickel and dime stuff to begin with.

[BR3W CITY]

You said "When I get my license"...

get a 5.3; it will give you plenty of power, for someone who has little experience behind th wheel. I don't even mean that in a belittling way, just that its the truth. With a cammed 5.3 you'll be somewhere in the middle 3's for horsepower, and torque to match. Combined with the way these old trucks feel going down the road, it will easily be the top end of what you can handle. Too many people are focused on building big numbers, yet have never driven their vehicle to the edge of what they already have.

Get the 5.3, toss a cam in it and have it tuned. It will make you plenty happy and give you the feel, sound, and even some efficiency to still be a useable DD. Drive the heck out of it, find where the edge of traction is, find where the edge of steering is, and drive it to that edge (safely).

Then, when you've conquered the truck as it is, build it up. You'll appreciate the gains in power more, and you'll also be a better driver overall for it. I'm not one to say young drivers should only have uber-safe-slow cars, as I think driving something with some real nuts forces you to learn to drive correctly. These old vehicles require focus, and some effort to drive unlike modern vehicles, and they teach you way more about driving in general. You can have just enough power in that truck with the 5.3 to haul ass, win a few friendly wagers with friends, tow a high school parade float, and still squeak out ~16 combined mpg so you'll have money left over for condoms.....no one wants to be the guy dropping a girl off at 10pm, cuz he only had money for a few gallons of premium...

[BigDan3131]

Heck you can get the little 4.8L and just add a non-intercooled turbo to it for the extra torque and still knock down decent mpg. Its not so much that our trucks are bricks as much as vehicle weight. With a 2 wheel drive we can lower it quite a bit to reduce drag and getting rid of weight you don't need helps too. But with a 4x4 you have more drivetrain loss, the height is higher and the tires are bigger and heavier.

[smoky02]

I have a 6.0 with a 4L60e and the rest of the mods I'm running are in my sig. But my gas mileage is around 10-12 and once I've gotten 15 mpg.

[softballnrd27]

Get a 5.3 learn it and when its time to get more power then throw a turbo on it and let it rip. nuff said lol!!

Seriously though, 5.3s are plenty powerful when tuned right. I love mine. Don't try and start with high HP, like BR3W CITY said you will appreciate the power you gain more.

[Hart_Rod]

Originally Posted by BR3W CITY

You said "When I get my license"...

get a 5.3; it will give you plenty of power, for someone who has little experience behind th wheel. I don't even mean that in a belittling way, just that its the truth. With a cammed 5.3 you'll be somewhere in the middle 3's for horsepower, and torque to match. Combined with the way these old trucks feel going down the road, it will easily be the top end of what you can handle. Too many people are focused on building big numbers, yet have never driven their vehicle to the edge of what they already have.

Get the 5.3, toss a cam in it and have it tuned. It will make you plenty happy and give you the feel, sound, and even some efficiency to still be a useable DD. Drive the heck out of it, find where the edge of traction is, find where the edge of steering is, and drive it to that edge (safely).

Then, when you've conquered the truck as it is, build it up. You'll appreciate the gains in power more, and you'll also be a better driver overall for it. I'm not one to say young drivers should only have uber-safe-slow cars, as I think driving something with some real nuts forces you to learn to drive correctly. These old vehicles require focus, and some effort to drive unlike modern vehicles, and they teach you way more about driving in general. You can have just enough power in that truck with the 5.3 to haul ass, win a few friendly wagers with friends, tow a high school parade float, and still squeak out ~16 combined mpg so you'll have money left over for condoms.....no one wants to be the guy dropping a girl off at 10pm, cuz he only had money for a few gallons of premium...

, Great advice!

[71K20chevy]

Lots of great advice here guys. I've been driving since I was about 7, driving vehicles since I was 9, but I've never really driven faster than 10 mph


I guess 5.3 it is. Unless I get a killer deal on a 6.0. Probably won't happen though, as 5.3's go for around $6-700 and 6.0's go for around $1000. I suppose that if one day I do decide to do a 6.0, it'd almost be a bolt in deal as the harness and whatnot would already be done.

Originally Posted by smoky02

I have a 6.0 with a 4L60e and the rest of the mods I'm running are in my sig. But my gas mileage is around 10-12 and once I've gotten 15 mpg.

That's actually REALLY close to what I had planned for a 6.0, and those numbers are lower than I expected



Thanks for helping my make up my mind! Although I'm sure it'll change 800 times between now and then.

[Clyde65]

I was going to recommend a 4.8 but I noticed in your sig that you have a K20, so I will pull that back and mimic what these fine folks have suggested.

[71K20chevy]

Yup, the truck weighs 5000 lbs, more like 6000 with me in it.

[Mr. 250r]

5.3 is your choice and don't be fooled about less cubes the 5.3 can be resleeved and made into a 427 from erl but its gonna cost a pretty penny

[68GMCCustom]

Originally Posted by Mr. 250r

5.3 is your choice and don't be fooled about less cubes the 5.3 can be resleeved and made into a 427 from erl but its gonna cost a pretty penny

if you've pulled it to do machine work....you can go ahead and replace it with something else just as easy. An LS1, LS2, LS3, LQ4, LM7, L92, L20, Etc. etc......they all bolt up the same. A GM Performance Parts LSX bowtie block would slip right in place and could be a 376ci all the way up to over 454ci.

That's my dream motor.....something similar to the LSX454 but in a 427ci just for kicks. LSX427......I like it. Some day.

[sqrlnts]

Originally Posted by BR3W CITY

and still squeak out ~16 combined mpg so you'll have money left over for condoms.....no one wants to be the guy dropping a girl off at 10pm, cuz he only had money for a few gallons of premium...

Classic!

[eagleuh1]

The 5.3 is a great motor, even towing and hauling loads. Very available. You can pretty much get your money back if you change your mind later and want the 6.0, or whatever new LS engines out later. Love mine.

[Houston Ben]

Here is my 5.3 with 6L80 I just got running, not the fastest thing in the world but it gets up and moves....and I still need to get it dyno tuned!

https://www.youtube.com/watch?v=WONDIfhAOiI

[71K20chevy]

I don't think it'll take much to go faster than my truck. Ben, I'm assuming the motor has had stuff done to it? Just from your video alone I can tell I'd be more than happy with a 5.3.

[Houston Ben]

Nope, nothing done to the engine except tuned to run as a stand-alone. I will be getting dyno tune in the future to squeeze all available hp an d tq out of it!

[71K20chevy]

Now that is impressive!