According to this: "<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
The early99 does not have the AIH like the late99-03.
The early99 has no indicator light showing that "cruise" is on. Late99-03 has a cruise light that will come on when you set the cruise control. " I have a late 99 truck. <o></o>
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However, my truck built date is 12/22/1998. According to Gooch's Coolant system write-up, my truck is considered pre-99 (pre-02/02/1999 built engine) and should use a conventional coolant charged with SCA. Am I right? Thx. Erwin<o></o>

 

where is the easist place to find the engine built date and sn. Does the VIN tell you that (original engine in truck)? I'd realy like to use the HD ELC instead of conventional coolant wit SCA charge, but can I?

 

The engine serial number can be found on the left valve cover sticker and also on the left rear of the engine block...near the oil filter housing.

 

Thx, I'll go look.

 

Here are some examples so you can know what you are looking for.
On the block stamping....the engine serial number appears horizontal. You are looking for the last 7 digits. In this example the serial number is 1226239
The other stamping that is oriented 90 degrees to the serial number is the last 7 characters of the VIN (MA28086)

 

So yes you are correct that you have a late 99 with a build date of 12/22/98 but that is not the same in terms of the coolant issue. The cutoff for the coolant type is 2/2/99 since this issue relates to the glue they used in the injector cups in the engine. 2/2/99 is when they change it so after that date, it was ok to use the ELC coolant.

That is my understanding at least so I hope it helps.