Thought I had a beauty ..... BUT
 

I bought this truck '72 Chev about 10 yrs ago, drove it only a few times then was stored for 10 yrs, retired into a small business that became a full time (semi retirement that was not semi) job. Recently business activity slowed down as patent rights expired, now really semi retired so decided to get the truck out and start to clean it up as my current ride an '05 Murano is beyond its limit. Prior to storing I did the brakes and installed 4 new tires, rode smooth, no vibrations handled perfectly. Have it out now and the same ride.
Thought Id start by finding out more about the truck, determined it had a long horn box, discovered that the options list on the glove box door had been removed so got the info package from GM, surprise surprise ............
Based on the spec sheets I got from GM.........
Appears interior has been changed to the Cheyenne or the Cheyenne Super, can't tell which one, spec sheet shows black vinyl bench seat, I thought that perhaps a different cab may have been put on the truck however the ID plate bears the correct VIN # and doesn't appear to have been replaced, rivets appear to be original, paint colour of the door matches cab paint etc so again it doesn't appear to have had a different cab installed, had large mirros which are on the spec sheet. This interior is in perfect condition, dash had a 3" split in the vinyl strip, seat looks new and rest of items. Another item that causes questions is the cab has a cargo light with inside switch that doesn't appear to be a standard item unless you have a Cheyenne and is not listed on the spec sheet as an option
Now THE REAL ISSUE OR CONCERN ........ Spec sheet shows the box to be 98" yet its 104", spec sheet shows wheelbase to be 127" yet I quickly measured it and thought it was 133" making it the long horn box wheelbase. As I've been working on the truck I noticed the gap between the front of the rear tire on the right side was different that the on the left side, left is 7", right is was 5", measurements taken from same points, bolt head to face of tire both sides. With that I measured the wheel base again, more accurately and left side is 134 1/2" vs right side as 132", measured center of hub cap to center of hub cap. Looking closer at things I noticed back side of cab to face of box, same points each side, right is 1 3/4" and left is 1/2"
Engine serial number matches spec sheet #
Where do I find the serial or model # of the transmission ???????
Am fortunate to have a vehicle ramp lift and have looked at the frame in detail, don't see it bent or twisted or welded to add length to the frame. It looks to me like someone took the vehicle as the spec sheet shows based on the VIN, exchanged the frame with a long horn frame (if there was such), exchanged the cab interior to one of the Cheyenne models. In the 60's and 70's I heard rumors that guys who worked on the assy line would order a base vehicle and have options installed that weren't on the order, wives tail or not ???
Where do I measure from point to point to get the wheelbase correct and determine what's wrong ? What's the proper measurements for the center of the axle within the wheel well openings ? Where would I find measurements of the frame ?
In spite of all the above for what I paid for it I'm satisfied, just want to solve the major issue of the wheel base, it drives and handles perfectly. Anyone willing to contact me direct may do so through my email address as liphook@i-zoom.net I'm in Ontario Canada, just outside Lindsay

Re: Thought I had a beauty ..... BUT
 

If I'm reading you correctly, it could be as simple as someone installing one leaf spring backwards... the locator pin isn't centered on the spring, and if the springs get bolted them up wrong (one correct, one backwards), it will cause a crooked axle and the visible symptoms you're describing.

Re: Thought I had a beauty ..... BUT
 

IIRC, Longhorns have an extended bed that is obviously added on.

What does your bed look like?

Post a picture of the transmission and it will be identified.

Re: Thought I had a beauty ..... BUT
 

JOEYDURANGO, thanks for comments, checked distance from center line (CL) of axel to CL of cross member below back of cab, 63 3/4" both sides. CL of axle to CL of front rear spring eye, 28" both sides. CL of axle to rivet on last cross member, 29 3/4" both sides. I removed hub caps and re measured wheelbase length, left side is 137 1/2" and right 136 3/4" so more accurately distance difference is 3/4", should this not be much closer to being the same both sides, is this difference of 3/4" something to worry about ??
BIGDAY160, your comment "extended bed that is obviously added" do you mean the welded seam on the box just behind the cab ? Your asking "what bed looks like", do you want a picture of the bed ??
Attached here are pictures of the transmission, wanting to know if its the trans as list on spec sheet from GM, they showed THM350

Re: Thought I had a beauty ..... BUT
 

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Re: Thought I had a beauty ..... BUT
 

Make certain, when you're measuring wheelbase, that the front wheels are perfectly straight (pointing forward). If they're turned even a little bit, it can make one side appear shorter, and one longer, since the steering pivot location is considerably far inboard of the outer hub area where you're measuring. Wouldn't be that difficult to be off by 3/4" if the wheels were turned even the slightest bit.

Re: Thought I had a beauty ..... BUT
 

If you suspect you have frame issues you need to “x” out he frame, or measure from the same points across frame in an x .. If it is square it will measure the same both times. 137 is long for even a 1 ton

Re: Thought I had a beauty ..... BUT
 

Vin number should be stamped on the frame, top behind power steering box, side under cab about where the front of the seat would be, maybe also passenger side under cab.

Re: Thought I had a beauty ..... BUT
 

Measure the bed to see if it is square.

Re: Thought I had a beauty ..... BUT
 

joeydurango, ........... Just happened to be sitting enjoying a cold one looking at the front wheels and thinking exactly what you mentioned in your reply, believe that was the problem, wheels not straight. Now the issue of the different distances measuring rear wheels within fender wells I think can be corrected when box is repositioned to get distance behind cab to front of box equal, one corner is 1/2" other is 1 3/4" .
streetrodchev, .......... yes, did that and corner to corner X within 1/2", length end to end the same, both sides as side to side is 1/2" difference. Feel that these will correct them selves when I correct gap behind cab, cab to front of box.
One issue I don't understand is the stake pocket dimensions, 1 dimension is 41 1/4" as spec, other is 58 1/4" vs 52" as spec for 104" box ???
thanks to all for commenting, ......... cheers