• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

6.0 heads on 5.3

Austin03Avalanche

Full Member
Joined
Mar 17, 2016
Messages
22
Location
Nebo NC
i have heard i can pull junk yard 6.0 heads and put them on a 5.3. Is this true and if so any big modifications needed ?
 
I believe you drop the compression ratio which means a loss in power.

Now if your rebuilding it and changing pistons then the answer is yes..
 
thanks i appreciate the advice. Im just so dissapointed in my avy i cant seem to get big power gains. i thank the bullydog i have is crap but theres no local tuners i know of due to the fact i live in the backwoods. My poor truck wouldnt spin a tire if you begged it to. I know torq mang is the factor here but surely i should see some gains from all ive spent
 
Yeah, the torque management kills off the line performance. Get it tuned by Nelson or Black Bear, both do good work and can help.. It's hard for a 5.3L to get a 6000 lb load moving quick, a few bolt ons and tuning will help, but only so much.. At the end of the day there's no "replacement for displacement" (love my 8.1L) and a lot have swapped in a 6.0L or 6.2L and love it.. Or maybe put on a supercharger..

But beware if you pull out the TM, or any of the above and you and start spinning those tires, the trans and rear end will be on your next mod list...


Good luck in your quest for power....


 
The 6.0L heads probably have larger valves, and therefore may not be compatible with smaller bore of the 5.3L.  You would need to check clearances, especially if you're running a cam with more lift and duration.
 
I agree completly with no replacement for displacement. I would love to have a drag truck truck but in all reality 6000lbs is alot to haul. So im trying to make a head turner not bust the diesel club that have took over all small block owners bragging rights in my lil town. :E: I just wanna play a little. i have a garage at my disposal and a grandpa who can build any small block but these LS motors leave us scratching our heads. We aint use to all this computer controlled HP 
 
If TBS is a throttle body spacer, I'd probably eBay that to someone you don't know. They don't work on these types of intakes.
What headers? I'm gonna potentially start a fight here but LS engines respond better to long tubes.
You already know the tuners are pretty limited. I had a Diablo Predator. It would remove TM but still had limits.
You can use several head castings but as said, on the dish Pistons of the 5.3, you will need to shave them a lot to get the compression up.
Good news is most any other LS block will fit. They're all the same size of the outside. Or most 5.3s can be bored to 5.7 and use off the shelf 3.89 Pistons. Or the stock 3.78 bore can take the flat top 4.8 piston. So much of these motors are the same that the combos are almost endless.
 
Austin03Avalanche said:
I agree completly with no replacement for displacement. I would love to have a drag truck truck but in all reality 6000lbs is alot to haul. So im trying to make a head turner not bust the diesel club that have took over all small block owners bragging rights in my lil town. :E: I just wanna play a little. i have a garage at my disposal and a grandpa who can build any small block but these LS motors leave us scratching our heads. We aint use to all this computer controlled HP 



They are really not that difficult, just go to summit racing or just do on-line search on LS Engines and you'll find more info than you can handle.. You can teach an old dog new tricks in this case... Youtube also has a wealth of info to help with how to videos...

http://www.summitracing.com/search/department/books-videos-software/section/books?N=4294951557%2B4294951556&keyword=LS%20engines

http://www.cartechbooks.com/ls-engines.html
 
mikeyjm1 said:
If TBS is a throttle body spacer, I'd probably eBay that to someone you don't know. They don't work on these types of intakes.
What headers? I'm gonna potentially start a fight here but LS engines respond better to long tubes.
You already know the tuners are pretty limited. I had a Diablo Predator. It would remove TM but still had limits.
You can use several head castings but as said, on the dish Pistons of the 5.3, you will need to shave them a lot to get the compression up.
Good news is most any other LS block will fit. They're all the same size of the outside. Or most 5.3s can be bored to 5.7 and use off the shelf 3.89 Pistons. Or the stock 3.78 bore can take the flat top 4.8 piston. So much of these motors are the same that the combos are almost endless.
Yes that is a thottle body spacer ,and believe it or not i swear by that. you can notice a difference between 3-5000 rpm. and the headers are shortys.
 
Austin03Avalanche said:
Yes that is a thottle body spacer ,and believe it or not i swear by that. you can notice a difference between 3-5000 rpm. and the headers are shortys.

Don't get Randy started on short vs long tubes... :p
 
ms38w said:
Don't get Randy started on short vs long tubes... :p


That's right, you tell'em not to open that door.. 


Good to hear from you, where have you been??
 
Randy said:
Yeah, the torque management kills off the line performance. Get it tuned by Nelson or Black Bear, both do good work and can help.. It's hard for a 5.3L to get a 6000 lb load moving quick, a few bolt ons and tuning will help, but only so much.. At the end of the day there's no "replacement for displacement" (love my 8.1L) and a lot have swapped in a 6.0L or 6.2L and love it.. Or maybe put on a supercharger..

Huh? I guess I'm going to have to get a picture of the pair of stripes I just laid out in front of the shop. Or a video of it. My stock 5.3 doesn't have any problem laying a little rubber, even with the G10 locked up. All I've done with it is a CAI with the stock air box & a K&N filter, and a Flowmaster 50.

That said, I'm thinking I'd like to do a tuner, even a 6.0 swap someday.
 
4.8, 5.3 and 6.0 are same heads...
Unless you get something special they should bolt right on as far as I have been told. If you look for rebuilt heads you will see them listed as fitting all three blocks.

This applies to stock heads only... If you go with something else I have no clue. I know that when I cracked the heads on my truck and was looking for new ones they all listed them as being for 4.8/5.3/6.0 so if you plan to just grab a set of OEM heads off a 6.0 your going to be disappointed.

Also make sure your O2 sensors are up to snuff and your cats are flowing well. Either issue can reduce power while not initially showing up until they throw a code.

And This may only apply for the '02 - '06 Avalanches, not sure about newer ones with AFM or flex fuel vehicles. They use a different setup. May be as easy as grabbing heads off another flex fuel vehicle.

Your likely to get a better bang for your buck by doing things like looking at the valve rocker ratios, adding better valve springs, doing a different cam that is more in line with what you do and a tune to go with it. Either getting an HP Tuner and learning how to do yourself or paying someone else to do it for you. There are better flowing heads out there but used with the proper cam and such will open up that 5.3 a bit more.

Personally I just need to get another ~5 years out of mine then I am going a fully blown 6.0 route...

Rodney
 
Randy said:
That's right, you tell'em not to open that door.. 


Good to hear from you, where have you been??

I got real sick several years ago.  Ended up costing me my job.  I eventually got better and got my job back, but I lost a lot.  I moved twice in one year.  I got on here once or twice about a year ago, but I haven't done much with the Avalanche in a long time.  Got rid of the sidepipes and went with conventional dual exhaust.  I have a few plans for the Avalanche, but keeping busy with other things.  All of my cars are 15-16 years old and always seem to need something.  I've been hanging around on the Facebook Avalanche group a bit, but there are lots of "trolls" on there looking to do what trolls do best.  Since being sick, I have to minimize that kind of stress or it puts me over the top because, well...you know how subtle I can be ;p  Hope all is well with you... :wave:
 
ms38w said:
I got real sick several years ago.  Ended up costing me my job.  I eventually got better and got my job back, but I lost a lot. 
Oh, that is terrible! Glad things are on the rebound!
 
Don't be a stranger, ms38w.

Miss your posts.

(y)
 
I know the feeling, I'm just getting over being sick. It took 4 1/2 months and 5 doctors to figure out what was wrong..

Great to see you posting I miss the banter...
 
I feel ya, Never nice to be sick... I went from being in shape and lots of energy to being over weight, have issues with knees and all I wanted to do was sleep...  While trying to get back into shape I have torn a meniscus in my knee, had shoulder surgery, and had a torn ACL repaired. Been trying to get back into shape without over doing it. And didn't realize it takes so much work to get back into shape.

While not sick it certainly is life changing so I can fully understand. Hopefully everything will be better now.

Rodney
 
Well,  if it's not one thing it's another.  Aside from the constant maintanence on 4 cars that are 16 years old, building an over-built shed and day to day "life happens" situations...I keep being plagued with various health issues.  The torn rotator cuff last November turned out to be bursitus, followed by a separate neck injury, causing the nerves in my neck to be inflamed...a great deal of pain all over.  The med's seem to be helping, so I'm hopeful again.  Still not hanging around on CAFCNA, but I do visit the Facebook page often, as many of you here are on there as well. 

Current issues with the Avalanche...

  fuel gauge stopped working.  Haven't messed with it yet, as that is the least of my vehicular concerns.  Other than that, it is running like a champ.  Lot's of power and fun to drive.  On a recent trip to NW Indiana, I saw as high as 18.5 mpg.  Average was closer to 14 mpg for the entire trip.

  No more side pipes...kept coming loose and failing state inspection...so I'm currently running a custom, traditional dual exhaust, but can't mount the spare under the truck.

  Still no air conditioning...might work on that soon.

I'm sure I'll get tagged for posting this here, but I figured it was a continuation of a previous conversation that was inadvertantly thread-jacked.  Sorry.
 
Back
Top