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quest
May 23rd, 2013, 11:20 PM
I have a 1965 K20 GMC.

I am thinking of putting my front diff and transfer case into my 1965 GMC 930. It is a cab and chassis 133 wheel base former tow truck .

According to GM's load ratings my front diff and suspension on the K20 have the same load rating as the front suspension of the 930 2WD cab and chassis.

I think I have dana 44 on the K20 but would like to know what front diff was used on one ton 4x4 trucks back in 1965. I have never seen an original one in person so just curious about this.

turbobill
May 25th, 2013, 02:59 AM
It's a Dana 44 with 8 lug hubs. The rest (externally anyway) seems to be the same as the 1/2 ton.

BarryGMC
May 25th, 2013, 03:30 AM
GM never offered a one ton 4x4 until the 73 model year. All 60 to 72 GM 3/4 ton 4x4 trucks used a Dana 44. Basically the dana 44 is the same on 1/2 ton and 3/4 ton except for brakes / hubs. Ironically the best dana front housing is found in suburbans and blazers from 73 to early 77. 3 inch tubes, the others are 2-3/4. My opinion is the coolest 60's one ton 4x4 axle is the dodge 300 series Dana 70. They are not to tough to find and fit a gm truck easily. If money is no concern use a GM D 60. Finally if you want duals you can use any d44 with integral hubs and dual wheel adapters from any gm d60 or independant one ton 4x4 until the early 2000's.

quest
May 25th, 2013, 07:50 AM
GM never offered a one ton 4x4 until the 73 model year. All 60 to 72 GM 3/4 ton 4x4 trucks used a Dana 44. Basically the dana 44 is the same on 1/2 ton and 3/4 ton except for brakes / hubs. Ironically the best dana front housing is found in suburbans and blazers from 73 to early 77. 3 inch tubes, the others are 2-3/4. My opinion is the coolest 60's one ton 4x4 axle is the dodge 300 series Dana 70. They are not to tough to find and fit a gm truck easily. If money is no concern use a GM D 60. Finally if you want duals you can use any d44 with integral hubs and dual wheel adapters from any gm d60 or independant one ton 4x4 until the early 2000's.

OK I didn't know this.
I have seen pictures of a one ton truck that is about to be restored and according to the owner its' been in the family since new, it is a 1966 GMC 930 panel with a Napco power pak, 327 4spd, 17.5 rims, original PTO winch.

Even though this is a one ton designation you are saying that it would still have a Dana44 front diff under it, is that correct? Is it possible that something different could have been offered here in Canada?
Thanks for the info.

BarryGMC
May 25th, 2013, 09:21 PM
Napco was an aftermarket conversion. GM went in house and started making their own 4x4 trucks in 1960. Its hard to say what that truck is. 1960-1972 GM never offered a K truck in its one ton lines.

ron david
May 30th, 2013, 09:14 PM
Napco was an aftermarket conversion. GM went in house and started making their own 4x4 trucks in 1960. Its hard to say what that truck is. 1960-1972 GM never offered a K truck in its one ton lines.
one could order a 1ton 4 x 4, just that it was a Napco installation, just the same as you could order it with a flatdeck or a crew cab body. you could also order a 4 or 5,000 series truck with a Napco installation. they would have a "K" designation in their ser.#.
ron

quest
May 30th, 2013, 11:11 PM
one could order a 1ton 4 x 4, just that it was a Napco installation, just the same as you could order it with a flatdeck or a crew cab body. you could also order a 4 or 5,000 series truck with a Napco installation. they would have a "K" designation in their ser.#.
ron

It turns out I have the heavy duty running gear version of the 1965 GMC K20 so when I swap my front running gear & TC over to the one ton chassis it will be pretty close to what would have been done if GMC was making them back then.
I'm pretty stoked about tearing everything down and get to working on it.

bigblockv6
May 31st, 2013, 12:50 AM
Curious to know are the Canadian 4wd trucks designated with K10 and K20 models versus the US models being K1000 and K1500? I know the 2wd versions are 910, 920 and 930.

quest
May 31st, 2013, 08:04 AM
Well it depends on the year, my one ton GMC is either a 64 or 65 and is a 930 however my 65 3/4 ton 4x4 is a K92534 and the original badge on the cowl says GMC920.
(1 of only 57 built of my model in 1965).
When ever I try to search parts online with U.S. vendors I get the most results searching Chev K20 but GMC K20 gets poor results.
I ordered my original documentation from GM vintage vehicle services in Oshawa Ontario and they also sent me a photocopy of the GM Truck specifications manual for 4x2 & 4x4 pickups, panels, suburbans, cab & chassis, vans. This book lists Chev or GMC 4x2's as C10, C20, C30 and 4x4's as K10, K20 but of course there is no K30.
Then it has several pages on standard spec for each and all the optionals specs. It has a section on all the optional engines, all the available truck configurations, transmissions, diffs etc.