How did you come to the conclusion that a turbo 5.3 would get better mpg than a turbo 6.0 in a 6000 lb vehicle in the mountains? Just curious......

 

I am concerned about mpg hwy. A turbo 5.3 will get better hwy mileage than a 6.0, or turbo....or at least that is what my hours of internet searching revealed.

Now towing...a 6.0 might get slightly better on the hwy, but I am concerned about all around economy and power.

I could have gone any route I wanted from duramax to 5.3. After alot of thought I settled on the 5.3 over the 8.1 and decided to swap in 3/4 ton running gear. I know of numerous k1500 burbs getting 17mpg or better N/A hwy in my general vicinity.

Motors are cheap enough (compared to a duramax) so if I am ever not satisfied with a 5.3 I can drop in a 6.0.

On the flip side, I dont know of anyone with a 6.0 suburban that gets better than 16mpg on the hwy. My dads 2003 sub gets 15- 16 mixed city and hwy and that's in Phoenix traffic.

Soooooo...Thats how I came to that conclusion. The turbo plan is to get the 5.3 where it needs to be power wise to tow.

 

I put the body lift in it cause my girlfriend and friends will pile in and we'll take off wheeling in the woods to go camping. The body lift helps the tires fit when the truck is flexed out. With the body-lift, keys, and rear spacers it sits 4 inches higher in the front and 3 inches higher in the rear. For a $160 the body lift is a great deal. As for towing seriously consider the 14 bolt H2 rear. Your 10 bolt will struggle to hold the power let alone with a heavy trailer. Also get the air bags that go in the rear springs. These trucks sag really badly with any weight. Mine tows Waaay better with them. For less than $90 you cant go wrong. As for fuel milage yeah its averaged 11mpg. I run 4.88 gears and only a 33 inch tire. Sure is fun though.

Link for Bags;

 

Oh it is for sure getting axles upgraded. I will probably settle on 4.10's and if I cant get a hummer rear I will get a eaton tru trac in the rear and ditch the Gov 80 bomb.

My rig has the auto ride suspension so that should help some with towing, but I will also get the bags...had planned to from the start.

I bet yours is a fun rig. I look forward to getting mine going. I am planning on going and picking up a second core support tomorrow. The bad thing about living where I do is everything is a 2-3 hr drive one way...no parts local

The DIC on my rig had an average of around 16mpg...who knows how accurate it is. The important thing is that you built what you want and enjoy it. Most people could care less about economy in a sub!

 

No takers??

I need to start doing some saving to purchase these parts...just need to know which ones and how much!

 

If you're towing just go small with a cam. Just get the cam, push-rods, and beehive spring package from texas speed for $630. A 212/218 would be solid as a towing cam. Normally with boosted motors you want a wide LSA Like a 116-120 for less blow by and more efficiency. However since this a turbo a little bit of exhaust overlap will spool it up faster making the truck more responsive. Get the cam with a 112 LSA which is normally a good balance.

Cam Package: https://www.texas-speed.com/p-1157-t...ve-spring.aspx

You need a 14 bolt semi floater. No way is it gonna last with boost while towing or plowing. Don't fear 4.10 gears. With you're tire decisions you'll be fine.

For a Torque Converter since you're towing 2,500 ish for the stall is a good number for pulling in 100F days. Just make sure you get a Trucool MAX transmission cooler. This is a fairly low stall speed but with the 112 LSA on the cam and a small 70mm turbo it will pull well. I've had good luck with 3 different converters from Hughes. It's pricey but you're gonna want the one with Lock-up and heavy duty sprags.

Converter: Hughes Performance Street Master Torque Converters 25-25L-HD - Free Shipping on Orders Over $99 at Summit Racing

For a turbo choice, I'm out of my league here. People on here seem do have great success with KB-Racing and Trick Performance. I'd talk it over with them, but 70mm is what I would run if I were towing merely for the snappy low end grunt.

 

Id say 4.10, as far converter neighborhood of id say betwen 2500-2800 depending on cam....

 

Thanks for the help guys! 11MPG expecially appreciate your taking the time to link everything out!

To be honest, I was kinda hoping to hear people suggest a bigger cam...but it is all a game of compromise if you want to tow and have performance. I will do some more research on that cam and similar packages, and see if I can dig up some sound clips for inspiration

As for the converter, I totally agree. A good converter is the kingpin for a tow rig. I have no problem spending 800 bones on a Hughes converter. They are a great company IMHO.

a 3/4 ton drivetrain minus engine is going to be swapped in when the time is right.

We are contemplating a big job change and purchasing our first house, so we are trying to save for a down payment as well. Turbo will come though, just might take a bit longer then I was initially preparing for. But that gives me time to get in the drivetrain to support it first.

 

Update!

I have installed the fender, core support, radiator, condenser, and hood today. Drove the truck around the back yard and let it idle for around two hours to make sure everything is good.

Also it has a brand new tcase in it!

I still need the following to get through inspection:
1. Airbag module reset
2. Passenger Hood hinge and mounting bracket
3. Passenger side headlight bracket
4. Both DRL lamps and bracketry
5. Hood Latch
6. Front Bumper Assy w/ fog lights
8. Fan shroud


That is it for factory parts.

I have a weird electrical issue to chase down with the drivers side, the seat auto adjusts when I engage 4wd or heated seats, also none of the lock or windows work on the drivers side switch.

One big step closer. Also, I used the aftermarket core support just because I am short on time, but I will change it out for an OEM in the future.

I should be on budget (Lordwilling) to get this through inspection for $2,500ish

 

So that cam is actually bigger than a triple 12. With the same duration. Not too shabby