Is this my original 71 frame?

[dfairchild19]

I am trying to figure out if the frame under my 71 is original. There are several things that make me question if it is. First, without even looking at the frame, the grill is off of an earlier first gen. The body mount brackets are bolted on instead of riveted on. The rear springs appear to be 1 ton springs and im not sure that they offered a 1 ton first gen?? It also had a body lift on it as if they were trying to clear the frame or something.

But then there are other things that make it appear original such as the closed knuckle front diff, the first gen transfer case cross member(??), and some brackets that still have their original rivets.

I dont think it was converted to 4x4 because i am almost positive that the front spring hangers are still riveted on. My thoughts are that it could be a 73 to 87 frame or that it could even be original with some of the rivets replaced with bolts.

Here are some pictures, Ill start a build thread soon but i need to know what gen frame i have to order 4" lift springs so i can get my 14b/d60 under there.
thanks in advance

[fine69]

To the right of where your steering column attaches to your gearbox your vin # will be stamped into the top of your frame.

Might take some work to clear it off.

But if your cab has never been changed it will match the vin on the cab.

[71blksuper4x4]

Does your rear shocks point the same way direction? Trevor

[67/72junkie]

Looks to be correct 71 k/20 to me with bolts in cab mount for some reason.I see it was originally a straight drive and has and extra trans crossmember.My 72 k20 has heavy duty rear springs and has extra thick leaf pack

[dfairchild19]

Originally Posted by 71blksuper4x4

Does your rear shocks point the same way direction? Trevor

yes the upper parts both point towards the front of the truck

[71blksuper4x4]

Original then....

[Livrat]

Looking at your pictures of the spring hangers tell me that it is a 69 or 70 frame.. (they have a shorter front spring perch on the rear springs than 71/72)

1st pic is a 70 frame.. 2nd is a 72 frame..

[dfairchild19]

Originally Posted by Livrat

Looking at your pictures of the spring hangers tell me that it is a 69 or 70 frame.. (they have a shorter front spring perch on the rear springs than 71/72)

1st pic is a 70 frame.. 2nd is a 72 frame..

well if this is the case then i am leaning towards a 70 because the springs are all 3 inches wide meaning that it would be a 70 becuase the springs on a 68 and 69 narrow to 2.5 inches unless the springs were changed somewhere along the way.

would this be safe to assume?
thanks for all of the input