[SOLVED] 07 burban 5.3 to 4.8 swap

[07burban88]

ok since I'm posting this, bad news. the oil pressure issue was not caused by the sensor, had bad rod bearings and scratched cylinder walls on the 5.3. previous owner neglected it bad. now the good news. a customer of ours with a 07 Tahoe is paying us to do a 6.0 swap so I get the 4.8 and 4l60e, both have only 115k miles on them, ecu and wire harness for core price for a whopping 800 dollars yay. i don't care about losing like 20hp, beats 2500 for a known good 5.3 flex lmg motor with 150k. the motor is a direct bolt in all go setup take me 2 days job. I work at a shop, but the motor mounts is confusing me. the 5.3 uses same part number both sides, the 4.8 is different part number left and right. should i use my 07 5.3 mounts or the Tahoe mounts?

 

[tooleyondeck]

The only difference in mounts that I am aware of are 4WD vs RWD, if your 5.3 mounts are good i would think you can just use them.

 

[Marky Dissod]

...
don't care about losing like 20hp, beats 2500 for a known good 5.3L flex lmg motor with 150k. the motor is a direct bolt in all go setup take me 2 days job.
I work at a shop, but the motor mounts is confusing me. the 5.3L uses same part number both sides, the 4.8L is different part number left and right.
should i use my 07 5.3 mounts or the Tahoe mounts?

You'll barely notice the loss of 20hp over 5000RpM.
You will absolutely notice the loss of 20ftlb from 1000-3500RpM, especially if your axle gears is 3.08.
At least ask him about axle gears? You want 4.10, for the love of all that is decent.

Use the stuff in your truck to mount the engine into your truck.

 

[07burban88]

sweet. ill be installing it tomorrow

 

[07burban88]

mine has the GT4 3.73 ratio

 

[strutaeng]

You should also get a new tune for the slightly smaller engine. Not sure if you had that in mind?

 

[Marky Dissod]

You should also get a new tune for the slightly smaller engine. Not sure if you had that in mind?

Doubtful - a smaller engine for a 6,000lb vehicle seems like a good idea?

 

[West 1]

A perfect running 4.8L will work fine, it will certainly drive better than your worn out 5.3L. For the price I would not hesitate unless I needed the extra power for towing heavy. Nothing wrong with a 4.8L, super reliable engine. Just a little less power.

While it is out take a few minutes and pull the oil pan for a new O ring on the pick up tube at the oil pump. You will never regret knowing that is new.

 

[Tonyrodz]

I had 2 separate 4.8s. 1 in my 05 Express van and 1 in my 03 Tahoe. Both had the 862 heads and both lost antifreeze. Both motors had a crack in the head(s). Not bad enough to lose a lot, but enough to be annoying. I used those AC Delco coolant tabs, and they worked great. I read the 862 heads are prone to cracks. Which heads are on your 4.8?

 

[07burban88]

well got the 4.8 in. I lifted the body off the frame, painted the frame, changed fuel pump and all wire harness loom and body to frame bushings. I'm a manager/mechanic at a shop so did it on a Sunday. made life a lot easier with the body out the way on a lift. took it on a 2-hour trip last night. this thing runs like a demon. way more power than the 5.3. ill pull it apart this Sunday and see the damage

 

[strutaeng]

Nice!

Body off frame FTW!

Are you gonna rebuild the 5.3? Otherwise just list it as a core or something. Depending on the damage, may be need minimal work or complete machine shop work and will get (more) expensive. Of course, you won't know until you open it up...

 

[Geotrash]

well got the 4.8 in. I lifted the body off the frame, painted the frame, changed fuel pump and all wire harness loom and body to frame bushings. I'm a manager/mechanic at a shop so did it on a Sunday. made life a lot easier with the body out the way on a lift. took it on a 2-hour trip last night. this thing runs like a demon. way more power than the 5.3. ill pull it apart this Sunday and see the damage

Way to go! Glad to hear it's running well for you!

 

[07burban88]

I'm hoping it's just failed oil pump or pun bearing but from sticking a camera down the spark plug holes I'm not very hopeful. and it only took a few hours to lift the body, and ya have so much space for activities it's the best, easiest and probably safest way

 

[West 1]

You must work fast, body off, frame painted, wiring replaced, new engine installed and test driven in one day! Wow. Nice work. Might have taken me a week.
Glad you have it on the road again. I had a 5.3L my brother had the 4.8L, drove both. Could not feel a difference in normal driving. I never raced him though.

 

[Marky Dissod]

I had a 5.3L my brother had the 4.8L, drove both. Could not feel a difference in normal driving.

Often because the 4.8L has a better axle gear ratio than the 5.3L vehicle.

 

[Charlie207]

Often because the 4.8L has a better axle gear ratio than the 5.3L vehicle.

I just ran out to look at the Built Sheet in the glovebox of my 4.8 plow-truck, hoping to see 3.73 or 4.10 gears, but alas it has the GU6 3.42s.

I was thinking I could swap gearsets into my GU6 Yukon, and got excited.

While I was out there I read the CEL codes, and it reads like Chinese New Year looks.

You'd never know by how gracefully it smashes into snowbanks.