Do I have a 5.3 Gen IV?

[Oilbrnr]

So I got this engine in a trade back in '08. It was supposed to be out of an Escalade which would have made it a 6.2, which it isn't.

The iron block clearly has the 5.3 and 4.8 Gen IV casting on the right sides front and rear with a BLUE paint dot on the 4.8. Seeing this, combine with the 243 casting heads, I assumed it was in fact a 4.8, however now that I'm closer to doing the swap to my K5 I've discovered on closer examination a couple of items that have me wondering if it might actually in fact be a 5.3.

First, it has 12594512 flex fuel injectors, second it has VLOM or a Valve Lifter Oil Manifold for Active Fuel Management. It does NOT have the VVT solenoid on the cam cover. All of this (other than the 243 heads) point to a LMG 5.3. Oh, and it does have the E38 ECM. From what I can find so far online, neither flex fuel or DoD was offered on the '07 4.8

I wanted to ask here first before I post on ls1tech, as they seem to be somewhat of a hostile group to noobs, which is kinda irritating. Is it possible to see the shape of the piston with the plug out, or feel it with a pencil for example?

Thanks for any help.

[whitels1]

The easiest way would be to pull the oil pan and check the casting number on the crank.

[Oilbrnr]

What is the torquing procedure to put the pan back on? Assuming I'll need a new gasket, anything else? Is there one particular casting number or could there be several different ones that GM used?

[Kim57]

On my 6.0 the head gasket has a tab that sticks out with "6.0" stamped in it.
I don't know if the 5.3/4.8 have the same thing.
Kim

[Oilbrnr]

Meh, I just talked to a co-worker that has an '07 Tahoe with AFM and FlexFuel. He said it was a 4.8. On the upside, he is pleased with the power and the way it tows his boat.

Bummed. Not sure it is worth pulling the pan.

[JNJchev77]

If you truly want to verify if it's a 4.8 or 5.3, pull the spark plug for piston one (or anyone for that matter)... shine a light while rotating the engine so you are able to see the top of the piston.

If the Piston is "dished" (has a concave lip towards the outside) it's a 5.3... If the piston head is flat on top it's a 4.8.

[Oilbrnr]

I'll take a look tonight.
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[ddubbs]

Glad I found this thread. Just bought a complete 5.3 for 550 bucks and now I will have to take a look. Thanks for the info!!!
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[ddubbs]

Glad I found this thread. Just bought a complete 5.3 for 550 bucks and now I will have to take a look. Thanks for the info!!!
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[Oilbrnr]

Its a 4.8

My favorite tool, a probably '30-'40 wooden handle ice pick from Babbitt Bros. Trading Ice Co. in my hometown of Flagstaff, AZ, confirmed it. It has flattops.



Guess I'll see how she does after the swap and work out the kinks, then start looking for a SC. I just can't get over how much they are USED! But it would be an interesting DD experiment. Decent power and mileage from a squarebody 4x...

Then again maybe I should just go look for a 8.1 and be done.

[Hart_Rod]

Originally Posted by Oilbrnr

Its a 4.8

My favorite tool, a probably '30-'40 wooden handle ice pick from Babbitt Bros. Trading Ice Co. in my hometown of Flagstaff, AZ, confirmed it. It has flattops.



Guess I'll see how she does after the swap and work out the kinks, then start looking for a SC. I just can't get over how much they are USED! But it would be an interesting DD experiment. Decent power and mileage from a squarebody 4x...

Then again maybe I should just go look for a 8.1 and be done.

Add a turbo and a nice cam and you should be close to 500 HP....

[ls1nova71]

Originally Posted by Oilbrnr

I wanted to ask here first before I post on ls1tech, as they seem to be somewhat of a hostile group to noobs....

We're not all that bad. Sounds like you already figured out what it is. I would put it in and run it, then if it doesn't have enough power for you, you can swap it out for a larger displacement engine later, won't be any fab work, just an engine r&r, could be done in a day.

[Oilbrnr]

Originally Posted by ls1nova71

We're not all that bad. Sounds like you already figured out what it is. I would put it in and run it, then if it doesn't have enough power for you, you can swap it out for a larger displacement engine later, won't be any fab work, just an engine r&r, could be done in a day.

I figured the same thing. It is always one of those cases where if you're going to go through all the work to do it, go big in the first place. BUT, my idea with this K5 is to use it as my DD, and the 'lil 4.8 might just be OK for the job.

I did a final run on the old Goodwrench a couple of weeks ago with Dynolicious running. You'all, don't be jelly of the hp or shifting speed:


Blazer
1977 Chevy K5
Mar 4, 2013, 5:52 PM
Acceleration
0-10 MPH: 1.42 sec
0-20 MPH: 2.63 sec
0-30 MPH: 4.31 sec
0-40 MPH: 7.88 sec
0-50 MPH: 10.89 sec
0-60 MPH: 14.06 sec
0-70 MPH: 17.83 sec

Elapsed Time
60': 3.33 sec @ 22.7 MPH
330': 8.73 sec @ 41.1 MPH
1/8 mi: 13.21 sec @ 55.8 MPH
1000': 16.90 sec @ 66.6 MPH
1/4 mi: 19.98 sec @ 71.8 MPH

Miscellaneous
Max Speed: 72.3 MPH
Max Acceleration: 0.48 G's
Peak Horsepower: 120 HP

Generated by Dynolicious







Don Leamon

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