Hi,

I have been working on rebuilding a Vortec 5300 but I am having trouble identifying the exact model. (Dont have the VIN) I was under the impression it is a Gen 3 LM7 but its stamped code I208. Which if im not mistaken makes it September 20th 2008 which would imply gen 4. Is this correct? If so were gen 3 blocks being produced at that time?


Timing cover has no sensor
Cam sensor is located at the rear of the valley plate
Knock sensors are in the valley

I thought these were purely gen 3 features

Any help is appreciated

 

Probably 1998, not 2008

 

I thought that but everything Im reading tells me that production for Gen 3 Vortec 5300 was 1999-2007 which is why Im a little confused.

A couple examples:
http://bdturnkeyengines.com/53l-lm4-lm7-l33-l59
https://www.onallcylinders.com/2018/...ads-cam-specs/

 

1208 might indicate something else. Gen III 5.3's were made between 1999-2007 model years. Not before or after.
You most likely have an LM7 or L59 if iron, or LR4 or L33 if aluminum.
1999 was the first MODEL YEAR, so it could have been made in December (12) of 1998 (08??)

 

Its "i208", I think the web font may be adding confusion. I am 99% sure its an LM7. (Iron block, no flexi fuel injectors) Its just the date code thats giving me pause before ordering parts. Interestingly the heads have very similar dates on them (862s)

Block & date code: https://imgur.com/a/naIuB6y
Head date codes: https://imgur.com/a/POsk9V0

Thanks

 

I wouldn't worry about ordering parts, the only differences during production were switching from mostly long and four short head bolts to all short for 04MY and the running change to Gen IV rods.
How deep do you plan on digging into this engine? You'll know which head bolts to use once you pull the heads off, and if you get the pistons out you will know whether you have pressed or floating pins plus the stouter rods.

 

You have a Gen 3, so you can order parts for any gen 3 application. Valley knock sensors, cam sensor in the back, etc etc.

 

Youll know if its 99-03 if it has the long and short head bolts or 04-07 if they're all the same length..the rest doesnt matter, all other gen 3 parts interchange.

 

Thanks for the help everyone. The head bolts are short on the ends and long in the middle so I guess it's 1999-2003/4. The i208 must refer to 1998. I guess that makes sense that it would take a few months before the vehicle is registered.

One other question I had was about cam bearing size. I have been reading later ones are a widened diameter. Do I need to be careful about the that?

 

Clearly you have a 99-02 or whatever it was.

They cast things like blocks, on a certain date; then they "season" em (leave em out in the sun, rain, snow, whatever) for a month or 2, then machine em, then assemble em, then ship em to a vehicle assy plant and build a vehicle around em, then ship em to dealers and sell em. The total ET between CASTING (the date you are reading) and the VEHICLE year model, can easily be 6 mo or more.

Since all cams for that gen of motor are the same, you can use the wider bearings (if there's really any such thing) without a problem. Just make sure the oil holes line up with the passages in the block properly when installing em. Personally I don't know if there's any difference or not, or whether maybe they've just discontinued the earlier configuration, because the later one fits em all just as well and there's no sense making and stocking 2 of em if 1 will cover em all.

 

I need an expert at reading castings. Is this one a DEC 24, 2005 casting?

 

RB04av--I've got a 5.3L Gen III on my bench right now that came out of a 2004 truck and it uses the CH-25 bearings! The CH-10's WILL NOT WORK.. So in addition to head bolt length changes, it seems that the cam bearings also might have changed in 04. The earlier-99-03- engines seem to take the CH-10's. The CH-10's are different sizes on the OD in addition to the width as compared to the CH-25's. On this block the bearing stamped #1 from the CH-10 box would simply pass right through the front, and 5th location of the block with no interference. The CH-25's fit perfectly.