What are the differences between 1998 and 1999 classic?

[L31MaxExpress]

Almost nothing changed between 98 and 99.

My buddy always had problems with his 2000 Tahoe until he started telling them it was a 98.

 

[89obsSB]

I've been down this road with both '99 Burbs and my '90 Burb (Suburbans carried the previous body style over in square body era too).
What worked a lot was to bring the VIN number in when buying parts.
Do you have another parts store to go to, or maybe just a different counter person at that one? I was fortunate at my local O'Reilly's (well local when I still lived in Stafford, but I still do a lot of my repairs there) that I got a very qualified person from the commercial account counter. They grew up in a third generation family run auto shop, and that kind of knowledge isn't found at the retail store level like it used to be. Back in the 70s when I started in the store my Dad worked in, and then we bought it in 1978, everyone who worked there, worked on their cars or trucks. Of course vehicles were much simpler then....
There was a young guy at my store who had grown up around GMT 400s and had one that he dailied, and worked on. I haven't seen his truck or him the last few times I've been at the store, so he may have transferred to another location. So there are youngsters out there who know what they're doing, ya just gotta find them!
Another thing; the way Rock Auto online catalog lookup is, where you have to plug in year, make, model and engine, may not be how all parts store computer catalogs are formatted. If it was, then the 5.7/7.4 vs. 4.8/5.3/6.0 should make a difference (since that's a good distinction between 400/800 trucks). Good luck with future purchases, hope this helps!

Suburban stayed square till 1991 I believe. I could be wrong. Same goes for the 3/4 and 1 tons. Correct me if I’m wrong.

 

[tayto]

Suburban stayed square till 1991 I believe. I could be wrong. Same goes for the 3/4 and 1 tons. Correct me if I’m wrong.

suburban, crew cabs and fullsize blazer/jimmy were squarebody until '91

 

[GoToGuy]

You could always be one step ahead. Go to " GMParts giant.com " use the find parts by entering your VIN, since your using the GM parts database it knows your vehicle by year, model, serial number contained in the VIN. Select the category, drop down for parts you want. Get the GM part number and the ACDelco will be listed also if available. You could the same thing on the ACDelco parts web site. With those numbers you have the correct numbers that can be crossed other part suppliers. I've done it often. Many part suppliers already use ACDelco numbers, it's just more efficient. Why reinvent the wheel. Many part supplier already have a part crosscheck built into their web site. Use GM or ACDelco number crossover on other supplier for the number at your local parts.
Before I could drive I had part time job in hometown " Auto Parts Store " with garage next door. 15 ft of catalogs, with a 3 ft area of all speed goodies. Edelbrock, Crower, Wiend, Holley, TRW/ Speed Pro, Isky, Lunati, there were a lot of Hotrods and factory hi performance. We also supported a lot of farm hardware, and had a hose bench. I made a lot of hydraulic hoses. I acquired some skills and training that was a good ROI. Good luck.

 

[2drXmobb]

I've noticed mines has emissions like the evap and abs module in place of a second battery tray compared to pre 99s but I've also seen some with the tray on 99s so maybe it's a state to state difference but either than that I can't think of a contrast between the years. 96-00 seems the same. Maybe injector differences also to the upgraded injectors.

 

[HHoldred88]

I have a similar problem with my 1988. they always go to the old square body page. sometimes I just have to type 1990 if looking up online parts that I know are the same on both years

 

[HotWheelsBurban]

suburban, crew cabs and fullsize blazer/jimmy were squarebody until '91

Burbs/Blazer/Jimmy/crew cab dual and single rear wheels were all on the Square Body (73-87 on regular pickups) through 1991 models. These models went over to the OBS/400 platform in late '91 as '92 models. The weight designation uses R instead of C for 2wd and V instead of K for the 4x4s. There's a lot of these '88-91 SUVs and crew cabs on the gmsquarebody.com website/forums.