'98 K2500 info needed...

[Spinner]

Looking at selling my '77K5 Blazer and buying a '98 3/4 4WD XCab SB, 5.7 Vortec, 5speed.  It's the 8 lug HD (or reg duty?) How do I know what gears it has, 3:73 or 4:10's? Or the tranny? Differential cap has 14 bolts. I have access to the codes in the glove box, what am I looking for?  It has 245/75/16's on it but I'd like to get some 285's. I pull a small boat or 2 ATV's or 2 snowmobiles every so often. If I move up in tire size, do I absolutely have to change the gears with those light loads? This truck is stock, only mod is a bug shield. Been in the '77 too long, I'm WAY behind.  Thanks!-

[Shaners]

I hope this helps...

http://www.gm-trucks.com/cgi-bin/ikonboard...3&topic=121

 

[RyanbabZ71]

check the glovebox for codes.  Write them down and take em to a chevy dealership or post here and we can help you to decipher (sp?) what the truck has in it.  

 

[Colorado Z]

Spinner, here some rear axle RPO codes for GM. Hope this helps.

GH0 AXLE REAR, 3.54 RATIO

GH2 AXLE REAR, 2.29 RATIO

GH3 AXLE REAR, 2.77 RATIO

GH4 AXLE REAR, 2.92 RATIO

GK9 AXLE REAR, 4.63 RATIO

GL3 AXLE REAR, 6.17 RATIO

GM1 AXLE REAR, 2.59 RATIO

GM3 AXLE REAR, 3.45 RATIO

GM8 AXLE REAR, 2.56 RATIO

GQ1 AXLE, STD RATIO

GS4 AXLE REAR, 3.70 RATIO

GTY AXLE, WIDE TRACK

GT4 AXLE REAR, 3.73 RATIO

GT5 AXLE REAR, 4.10 RATIO

GT7 AXLE REAR, 3.33 RATIO

 

GT8 AXLE REAR, 4.10 RATIO

GU1 AXLE REAR, 2.41 RATIO

GU2 AXLE REAR, 2.73 RATIO

GU4 AXLE REAR, 3.08 RATIO

GU5 AXLE REAR, 3.23 RATIO

GU6 AXLE REAR, 3.42 RATIO

GV2 AXLE REAR, 5.83 RATIO

GV4 AXLE REAR, 3.36 RATIO

GV8 AXLE REAR, 2.72 RATIO

GW4 AXLE REAR, 3.31 RATIO

GW6 AXLE REAR, 3.27 RATIO

GW9 AXLE REAR, 2.93 RATIO

GX3 RATIO,TRANSAXLE FINAL DRIVE 3.33

GYS RATIO TRANSAXLE FINAL DRIVE 3.65

G44 AXLE REAR 3.07 RATIO

G5O SPRING REAR, HEAVY DUTY, VAR 1

G51 SPRING REAR, HEAVY DUTY, VAR 2

G52 SPRING, RR, 15000 LBS

G60 SPRING REAR, AUXILIARY

G66 LEVEL CONTROL, MAN, AIR

G67 LEVEL CONTROL, AUTO, AIR

G69 LEVEL CONTROL, AUTO, AIR, HD

G72 AXLE REAR, 2.14 RATIO

G75 AXLE REAR, 3.62 RATIO

G80 AXLE POSITRACTION, LIMITED SLIP

G87 RING GEAR, 8.50 INCH

G89 RING GEAR, 7.50 INCH

G92 AXLE REAR RATIO, PERFORMANCE

G9S AXLE REAR RATIO, ECONOMY

 

RPO Codes HA3 ? H04

HA3 AXLE REAR, 5.29 RATIO, SINGLE SPEED

HC4 AXLE REAR, 4.56 RATIO

HC7 AXLE REAR, 5.13 RATIO, 7500 LBS, SINGLE SPEED

HC8 AXLE REAR, 3.21 RATIO, SINGLE SPEED, TRUCK

HE3 AXLE REAR, 3.07 RATIO, 3500 LBS, SINGLE SPEED,

HF7 AXLE REAR, 4.56 RATIO, IOOOO LBS, DANA 70, SINGLE

HF8 AXLE REAR, 4.88 RATIO

HK1 AXLE REAR, 2.87 RATIO

HK9 AXLE REAR, 5.86 RATIO 10000 LBS, SINGLE SPEED

HPR HEADLAMPS, DUAL, RECTANGULAR

H04 AXLE REAR, 4.11 RATIO, SINGLE SPEED

[Spinner]

Thanks, but I don't see my codes? Copied these this AM and double checked-here they are

After the VIN#, 141.5

AE7 AM7 A20 C6P C60 DEZ E63 FE9 FF6 FF7 GMC G15 JB7 K34 K60 L31 MW3 NA4 NF2 N33 R9A R9V R9Z SLL UM6 UQ5 VB3 VG3 VK3 VXS V73 XGK X88 YD3 YD6 YGK ZGK ZQ3 ZY1 1SA 1SZ 26C 26I 50U 6GK 7GK RC/CC (smudged, I think RC/CC)  U8624  26C

 If these don't make sense to anyone I'll try the Chevy dealer.  Thanks again!

[Colorado Z]

Here are some of your codes: I wasn't able to get the others from my list, and I can't post the entire list because of the size restriction. Unfortunately, your axle ratio and other pertinent info is not included in this list.

Hope it helps anyway.

AE7 SEAT, FRT SPLIT DRIVER PASS EASY ENTRY

AM7 SEAT, RR, FLDG

A20 WINDOW, RR QUARTER VENT SWING OUT

C6P GVW RATING, 8600 LBS

C60 HVAC SYSTEM, AIR CONDITIONER FRT MAN CONTROLS

E63 BODY EQUIPMENT, FLEETSIDE, PUBX

FF6 ARM, TORS BAR SPRING ADJ (E)

FF7 ARM, TORS BAR SPRING ADJ (F)

JB7 BRAKE, POWER, DISC, DRUM 8400 L85

K34 CRUISE CONTROL, AUT0MATIC, ELECTRONIC

K60 GENERATOR, 100 AMP

L31 5.7L V8

NA4 EMISSION SYSTEM, GVW,AB0VE 8500 LB

NF2 EMISSION SYSTEM, FEDERAL, TIER 1

N33 STEERING COLUMN, TILT TYPE

UM6 RADIO, AM/FM STEREO, SEEK/SCAN, AUTO REV CASS,

UQ5 SPEAKER SYSTEM, 4, DUAL FRT DR MTD, DUAL EXTD RGE

VB3 BUMPER RR, STEP CHROME, IMPACT STRIP

VG3 BUMPER FRT, IMPACT STRIP

VK3 LICENSE PLATE, FRT MOUNTING PKG

ZQ3 SALES PACKAGE, DRIVER CONVENIENCE II

ZY1 COLOR COMBINATION, SOLID

50U PRIMARY COLOR, EXTERIOR BLUE WHITE (91)

 

[Spinner]

Got it from the dealer! 4:10's with the New Venture tranny with aluminum case O/D.  Thanks colorado, I was wondering about the alternator too.  I'll be scribbling your post down for future refence.  Where'd you find those codes?

[Colorado Z]

I think this is the site I got them from originally, and I scrounged around a little bit more for my individual truck's codes.

http://personal.clt.bellsouth.net/clt/m/g/...ds/rpomenu2.htm

 

[Kansas Kid]

Just some more info on the transmission.  It will be a NV4500, which is a very strong and reliable unit.  It has been around for a long time, and both GM and Dodge still use it on some 3/4 ton and up trucks.  The gear ratios are as follows....

1st- 5.61

2nd-3.04

3rd-1.67

4th-Direct (1.1)

5th-0.75

As for needing to change the gears after putting some 285's on your truck, that shouldn't be necessary since you have 4.10 gears.  The Vortec 350 and a 5-speed make a great towing combo.

[Spinner]

Much thanks to Colorado Z and Kansas Kid.  Will return after purchase....