Hog,

I have yet to see the alleged smaller injectors. I own a 2000 with 5.3 Auto and it has 24 lb injectors.

I have never worked on a 4.8 manual transmission truck so I don't know what they had.

You stated the L33 was not available in a 1/2 ton. I believe you miss typed that, as far as I know it was only available in 1/2 ton. I am just not sure of the exact requirements but I believe 4x4 was one of the requirements. I also believe only something like 25% of the trucks produced from 05 - 07 had the L33


LM7 vin code was T
L59 vin code was Z
L33 vin code was B
LM4 vin code was P

Yes the L33 is actually cheaper then the LM7 replacement engine especially if your eating the core charge...

I was planning on getting one soon!

 

When mating a 99 block with a 03 heads What head gasket will i need to use? the 99 or the 03? They both have the same thickness compressed.

 

You need to check the head first!!! In 99, some of the 862 heads had a notch in the deck surface.

If you do NOT have the notch then you can use either type.

If your heads have the notch in the deck surface, you can only use the Fiber type gasket.

There is a good explanation here... Gen III GM Small Block: Engine Builder

I copied and attached the pictures from that document.

 

Good news the new heads do not have the notch and the gasket is head specific not block correct as long as its for the 5.3

 

That is correct. Either style of gaskets for the 4.8/5.3L will work since you have no notch. The 4.8L/5.3L share the same block and bore size. They also use the same head with the exception of the L33 option.

 

I typed that the L33 WASNT available in the LIGHTEST of the 1/2 ton trucks, because it WASNT. You couldnt get the L33 in a 1/2 ton RCSB, just the heavier versions of the 1/2 tons. Sorry if that wasnt worded clearly.

L33 required 4wd extended cab with standard length box.

Thats interesting about the injectors. Your truck is proof positive about the larger injectors. I always thought it would be weird of GM to have an injector split between the manual/auto 2000 4.8 vehicles.
The difference(if there is one) would show up in the calibration I would assume? Probably just the 99(19-21) and 2000+(24-25pph).

peace
Hog

 

Yes, I miss understood what you were posting in reference to the L33

As far as the Injector Flow goes. Yes, The calibration file would show if it was a smaller injector. I have not seen one in person as of yet. I just looked and according to the factory tunes on tune file depot there is a 99 OS for 5.3L that shows a 21Lb injector rateing.

The 99 Silverado OS in question is 09373372 listed as 5.3 on tune file depot
and shows an injector flow rating of 21.763701 Lbs/Hour

I went through the few stock tunes I have and I have a PCM that I pulled the tune from that matches and confirms this data with the same OS. This was a 5.3/Auto 2wd truck according to the PCM I have. I also pulled the tune from another computer for someone that did an engine swap and the ECU has an OS of 09379910 for a 5.3/auto 4x4 that also shows the same injector rating.

The original OS in my 2000 was 09381344
and shows an injector flow rating of 24.801938
Which matches the tune on the site.

My OS has since been upgraded to the latest factory OS through the dealer and still shows the same flow rating on the injectors.

If only we knew the part numbers on the injector's in question.

Hope that helps!

 

Ok back to the topic I started.

I just want to make sure I have what i need. I am swapping the cam and heads and installing headers. on top of the obvious mentioned before

Gasket and parts list
Head gasket kit
Head bolts
Valve cover gasket kit
Intake manifold gasket kit
Timing chain
timing cover gasket
water pump gasket
exhaust manifold gasket
oil pan gasket ( just for good measure)

oil, lube(everyone needs lube) coolant
an *** load of patients

am i missing something that i need or should be doing or replacing while i am doing this?

 

Suprised no one has brought this up. So, what casting numbers do you have? Sorry if i missed it. Are you aware that some of these earlier castings from "castec" had an issue with cracking?