Differences to 1999

jvthundercat

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I have and have had several GMT400's. I just picked up a rare 1999 Crew Cab short box K3500. Been looking for a long time. I thought the 99's and 00's were different.
I would like to know what is the same and what is not from 98's.
 

df2x4

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Same as 96-up.

Technically '98+ as the PCM changes you mentioned occurred then. '96-'97 were the odd black boxes that you can only tune with JET DST or TunerCAT (AFAIK), '98+ are supported by HPTuners.

I agree though, I don't think the '99-'00 classic body style trucks were much (if any) different from a '98.
 

454cid

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I have and have had several GMT400's. I just picked up a rare 1999 Crew Cab short box K3500. Been looking for a long time. I thought the 99's and 00's were different.
I would like to know what is the same and what is not from 98's.

In 2000 the 454 lost it's rear o2 sensors.
In 99 the Silverado trim package went away, and became the LS.
In early 99 the axles switched to synthetic gear lube... I've seen a month posted, but I never remember.
There is a date split for the oil filter for the 454 in 99..... early is the ph1218, late is the ph454 like the 8.1L got.

There are other differences that happened prior to 98, too..... fuel lines became quick connects, pushrod size in the 454, forged lower control arms don't date to 88.
 
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