Thread: LQ9 questions
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Old 05-16-2009, 09:01 AM
1badchevelle 1badchevelle is offline
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the only way to tell is the RPO number or by looking at the piston design. LQ4's have a dish, 9's have a flat top.
It is very simple to tell. The way I have always done it to know without a doubt is pull a spark plug out and bring that cyl to tdc and shine a light in the
cylinder. If you cant see the top of the piston turn the crank a little then use a coat hanger with the end folded over (to make it dull) and feel across the top of the piston if it is flat all the way across it is an LQ9 if you feel it raise up near the edge of the piston its an LQ4.

The only numbers on the back of the Block Are the Casting numbers and the Engine size. There is also a Foundry Identification mark on the back.

As far as Iron 6.0L engines go. 99 and 2000 had Iron heads with an 873 casting. In 2001 They started using aluminum casting 317 and 035 Heads. All Iron engines from 99-2002 were cabale actuated. In 2003 they started using electronic DBW set ups.

How ever there is ocasionally an exception to the rule and comercial vehicals often follow different production time lines. I have seen an 03 3500 comercial use work truck that was equipped with a cable actuated Throtle body. That maybe a case were GM was useing up inventory in In 1ton applicatioins that were to be used for comercial applications.
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