Seeking similar build VIN for GVWR cross referencing

[Winda Liqqer]

Hey all,

Seeking the last 8 digits of someone's VIN that is same/close to my truck. Dealerships cannot go to 1989 to dissect VIN for GVWR/GCWR however they can read 1990+. From what I gather anyone with a 90/91 would be my best case scenario.
*My glovebox build tag is well worn and the door decal is beyond faded*

Me:
1989 RCSB (Sierra SLE, stepside)
K1500
5.7 TBI
Auto. (700r4)
3.73 gearing
10 bolt axle
Light duty brakes
Leaf springs #tbd
A/C
C/C
Power windows/locks
Bench seat (no split)


My goal is to keep within legal GVWR limits and see what can be legally towed (albeit not much with this old girl). Online info is conflicting at best, once this is sorted out I'll report back legit numbers for the sake of future forum surfers.

Much appreciated

 

[1998_K1500_Sub]

I found this in the 1989 GM service manual, it makes reference to the braking capacity via reference to the forth digit of the VIN. This doesn't directly answer your question but it's a point of reference and gives some perspective of the vehicle's ability to handle load.

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The above image came from this page (from the bottom left):

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Then there's this:

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[RichLo]

^ wow, I'm surprised JN1 was a thing on a full size truck... no vacuum assist!

 

[Winda Liqqer]

Thank you @1998_K1500_Sub, that screenshot is a valuable one for lots of people. Still on the hunt for a relevant GCWR article or VIN to see what can be legally trailered.

I've since deduced my GAWR (gross axle weight rating)
Front 3350#
Rear 3750#

 

[Caman96]

^ wow, I'm surprised JN1 was a thing on a full size truck... no vacuum assist!

I’m surprised it’s even a thing.

 

[Erik the Awful]

The last eight won't tell you any of that. To be honest, it sounds like you're trying to scam a title for a tag that won't raise suspicions.

 

[Winda Liqqer]

Erik, you got me. Scammer here. Nah I’m kidding though I do understand how or why you’d think that.

Since my last post I’ve scoured cars.com, carsforsale.com and eBay for 1990+ VINs (all readily available). Have not phoned a dealership yet with those digits, will update if any useful data comes of it.

 

[GoToGuy]

Why don't you try the GM heritage website, download the owners handbook, the glove box thing, nobody looks at. It has trailer ratings listed in it. Or an '89 and '90 will be the same.
Notice the vin carries limits based on not how much can carry but how much your brakes can safely stop.

 

[Caman96]

An 89 RCSB 5.7 3.73 10 bolt…good guess it has JB3 brakes. Even with everything thing in good condition, I wouldn’t tow more than 1500-2000lbs. maybe.

 

[L31MaxExpress]

^ wow, I'm surprised JN1 was a thing on a full size truck... no vacuum assist!

The G-vans came with JB1 IIRC that did not have a vacuum booster as well. The most basic G10s came with that. Inline 6, 3 on the tree, manual brakes, manual steering and no ac.