Got a new truck!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

CDF302V8 · 06-01-2009, 04:21 PM

I got a 1979 GMC for free, last week. Its rough, but it will be a good winter beater or trail rig.

Since I have never owned a Chevy or GMC i dont know much about them, so how how would i figure out what gear ratio i have...or transfer case?

JohnC · 06-01-2009, 04:38 PM

Is that a real pic, or one of those pictures that they make look like a painting?

Man anything free is a good deal!

CDF302V8 · 06-01-2009, 07:13 PM

Quote:

Originally Posted by JohnC

Is that a real pic, or one of those pictures that they make look like a painting?

Man anything free is a good deal!

That is a real pic, i just edited it some.

Oh yeah!

Rollinsqrbdy · 06-01-2009, 09:21 PM

Nice score! But it does look like a real kool drawing or something like a oil painting.

MrBeast · 06-01-2009, 10:22 PM

there is a very good chance that it has a 4.10 ratio rear, and the tranny is either a TH350 or a TH400 the easiest way to tell is the TH400 has a pan that looks like a sail boat, the th350 has a pan that is square with a triangle missing from one corner.

If it is a manual the transmission will be a SM465, and the Tcase will most likely be a NP205, if it is an auto the Tcase can also be a 205, but it could also very well be a NP203, they put both in, the way to tell is to look at the shift boot, if it says 4 hi, 4low and then says lock at each end, with a neutral in the middle, that is a NP203, the 205 is idenitified by the fact that it is a gear driven transfer case and it can be difficult to shift.

The 205 case is heavy made out of solid cast iron, and will have a PTO port on it.

IF you cant figure it out, post some pics and I will let you know what you have.

Being a K-20 it has a 10 bolt front axle up front, and the rear will most likely be a 14 bolt, but in the 3/4 tons they put both semi and full floaters in em, the easiest way to tell is weather or not the yoke carrier bolts into the front of the pumpkin, if there are no bolts around it, it is a semi floater.

But really post some pics is your best bet at getting things identified.

C-10volvo · 06-01-2009, 11:57 PM

A little HDR action huh?

If the truck has low enough miles you can trust the build sheet that should be in the inner fender of the truck.

72 CustomCamper · 06-02-2009, 12:04 AM

Judging by the pic it looks like a 1/2 ton automatic with full time 4x4...

Chuck

Dooley · 06-02-2009, 08:06 AM

The standard axle ratio for a 1979 K10 was 4.11 except in CA where it was a 3.07, the base transmission was a 3 speed stick.
Available axle ratios for the K10 included,
2.76
3.07
3.40
3.73
4.11
All automatic transmission equipped trucks in 1979 came with the 203 transfercase. The 205 was not offered with automatic transmission until 1980 in squarebodies.

SBTork · 06-02-2009, 09:38 AM

Free is good. Judging by the picture, it looks like you may need some new cab mounts on the drivers side.

CDF302V8 · 06-02-2009, 03:41 PM

Quote:

Originally Posted by Dooley

The standard axle ratio for a 1979 K10 was 4.11 except in CA where it was a 3.07, the base transmission was a 3 speed stick.
Available axle ratios for the K10 included,
2.76
3.07
3.40
3.73
4.11
All automatic transmission equipped trucks in 1979 came with the 203 transfercase. The 205 was not offered with automatic transmission until 1980 in squarebodies.

Thanks for the info!

Quote:

Originally Posted by SBTork

Free is good. Judging by the picture, it looks like you may need some new cab mounts on the drivers side.

Yeah, the door doesnt shut fully.

06-01-2009, 04:21 PM	#1
CDF302V8 Registered User Join Date: May 2009 Location: Holland, Michigan Posts: 12	Got a new truck!! I got a 1979 GMC for free, last week. Its rough, but it will be a good winter beater or trail rig. Since I have never owned a Chevy or GMC i dont know much about them, so how how would i figure out what gear ratio i have...or transfer case? Last edited by CDF302V8; 06-01-2009 at 04:22 PM.

06-01-2009, 04:38 PM	#2
JohnC Registered User Join Date: Feb 2009 Location: Oklahoma Posts: 7,461	Re: Got a new truck!! Is that a real pic, or one of those pictures that they make look like a painting? Man anything free is a good deal!

06-01-2009, 09:21 PM	#4
Rollinsqrbdy Registered User Join Date: Aug 2008 Location: Dexter, N.M. Posts: 1,082	Re: Got a new truck!! Nice score! But it does look like a real kool drawing or something like a oil painting. __________________ Its Kool to be a square 2013 Chevy Silverado Z71 w/ 7" lift and 35" Nitto's 1985 C-10 ......My dream truck (under construction) 1984 k 10 Silverado...6" lift with 38.5 super swampers New Mexico Member --- Member of the Square Body Club--- Last edited by Rollinsqrbdy; 06-01-2009 at 09:21 PM.

06-01-2009, 10:22 PM	#5
MrBeast high-Tech Red Neck Join Date: Feb 2008 Location: Livingston, MT/On my boat WA/BC/AK Posts: 2,294	Re: Got a new truck!! there is a very good chance that it has a 4.10 ratio rear, and the tranny is either a TH350 or a TH400 the easiest way to tell is the TH400 has a pan that looks like a sail boat, the th350 has a pan that is square with a triangle missing from one corner. If it is a manual the transmission will be a SM465, and the Tcase will most likely be a NP205, if it is an auto the Tcase can also be a 205, but it could also very well be a NP203, they put both in, the way to tell is to look at the shift boot, if it says 4 hi, 4low and then says lock at each end, with a neutral in the middle, that is a NP203, the 205 is idenitified by the fact that it is a gear driven transfer case and it can be difficult to shift. The 205 case is heavy made out of solid cast iron, and will have a PTO port on it. IF you cant figure it out, post some pics and I will let you know what you have. Being a K-20 it has a 10 bolt front axle up front, and the rear will most likely be a 14 bolt, but in the 3/4 tons they put both semi and full floaters in em, the easiest way to tell is weather or not the yoke carrier bolts into the front of the pumpkin, if there are no bolts around it, it is a semi floater. But really post some pics is your best bet at getting things identified. __________________ "He used to be a pretty nice feller, now he's a welder!"

06-01-2009, 11:57 PM	#6
C-10volvo Registered User Join Date: May 2003 Location: Lake Oswego, Oregon Posts: 1,028	Re: Got a new truck!! A little HDR action huh? If the truck has low enough miles you can trust the build sheet that should be in the inner fender of the truck. __________________ Ken Morgan For fun: 1964 Volvo 122 For slow: 1984 Chevrolet C-10 For everything else: 1997 BMW M3

06-02-2009, 12:04 AM	#7
72 CustomCamper huh ??? Join Date: Nov 2002 Location: Fredericksburg,Va. Posts: 3,369	Re: Got a new truck!! Judging by the pic it looks like a 1/2 ton automatic with full time 4x4... Chuck __________________ 90 Blazer Silverado 350w/ 700R4 and 32" Kelly's "I am a bomb technician. If you see me running try to keep up!"

06-02-2009, 08:06 AM	#8
Dooley Registered User Join Date: Mar 2005 Location: North Coast Posts: 1,012	Re: Got a new truck!! The standard axle ratio for a 1979 K10 was 4.11 except in CA where it was a 3.07, the base transmission was a 3 speed stick. Available axle ratios for the K10 included, 2.76 3.07 3.40 3.73 4.11 All automatic transmission equipped trucks in 1979 came with the 203 transfercase. The 205 was not offered with automatic transmission until 1980 in squarebodies.

06-02-2009, 09:38 AM	#9
SBTork Garage wrench Join Date: Feb 2008 Location: LaCrosse, WI Posts: 1,855	Re: Got a new truck!! Free is good. Judging by the picture, it looks like you may need some new cab mounts on the drivers side. __________________ -Adam 90 V1500 GMC Suburban 350/700R4/NP241..... 01 Saturn SL1 stock DD.....



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