Jeff, I think Jim is looking for a breakdown of the model number. Ironically it was two years ago to the day that this same topic came up on the Forum.
As Harry Bursell explained the International Harvester Cub Cadet and Cadet Product Codes / Model Designations 1/11/13:
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Following are IH Codes for Tractors/Riders with Serial Number Tags having a letter "U", with
seven digits to the left of the U, and six digits to the right of the U.
First three digits (to the left of the U) identify Product Code. Next four digits identify the Model Designation. Finally, the six digits (following the U) identify consecutive unit build number.
For example, for the unit numbered 2050042U123456 = The first three digits 205 identify this tractor as a Cub Cadet Garden Tractor, and the next four digits identify it as a Model 86. The six digits after the U identify it as the 123,456 tractor built.
[End HB]
But it seems Myron Bounds has the best grasp of the topic, as Kraig shared the following on 1/11/13, quoting Myron:
[Begin Quote MB]
Hi Kraig....
I like to share info as you may have noticed. No secret "decoders"........
-)
What follows is info I got some from Ken Updike posting & my own observations: what's here is accurate but as yet I do not want to say its definitive. I may have missed a couple of numbers....
1. IH kind/codes were not used up through the 125.
2: The first three digits of the kind code for Cub Cadets is always 205.
3. The fourth digit may be part of the first three but but I suspect that it was an unused position for four digit model codes. IH never got past three digit model codes (the three immediately preceding the "U". The U, by the way, indicates it was manufactured in the US of A. This was made clear to me when I got to checking some kind codes for the big IH tractors where some were manufactured in Mexico, Canada or Britain as well as the US.
Model Codes:
0036 = 73
0037 = 106
0038 = 107
0039 = 126
0040 = 127
0041 = 147
0042 = 86
0043 = 108
0044 = 109
0045 = 128
0046 = 129
0047 = 149
0048 = 169
0050 = 800
0053 = 1000
0056 = 1200
0059 = 1250
0065 = 1450
0067 = 1650
0070 = 1650 (mod 856)
0203 = 147
0205 = 149 (vemeer mod 834)
0206 = 149
0207 = 86
0208 = 86
0209 = 108
0210 = 108
0211 = 109
0213 = 109
0217 = 128
0218 = 128
0220 = 129
0221 = 129
0222 = 129
0223 = 129
0224 = 149
0510 = 800 (hvc)
0520 = 800 (hvc)
0540 = 1000
0550 = 1000 (hvc)
0570 = 1200 (hvc)
0580 = 1200 (hvc)
0581 = 482 (ccc made for IH)
0582 = 582 (ccc made for IH)
0583 = 582 special (ccc made for IH)
0584 = 682 (ccc made for IH)
0585 = 782 (ccc made for IH)
0586 = 982 com. (ccc made for IH)
0587 = 1282 (ccc made for IH)
0588 = 982 com. (ccc made for IH)
0589 = 982 com. (ccc made for IH)
0590 = 1100
0591 = 482 w/gd
0592 = 682 w/gd
0593 = 682 w/hydraulics
0594 = 782 w/hydraulics
0595 = 982 w/hydraulics
0596 = 582 special
0597 = 482 (ccc)
0598 = 582 (ccc)
0599 = 582 special (ccc made for IH)
0600 = 682 (ccc made for IH)
0601 = 782 (ccc made for IH)
0602 = 982 com. (ccc made for IH)
0603 = 1282 (ccc made for IH)
0604 = 982 com. (ccc made for IH)
0605 = 982 com.
0606 = 782D (ccc made for IH)
0610 = 1250 (hvc)
0630 = 1250 (hvc)
0660 = 1450 (hvc)
0670 = 1650 (hvc)
0606 = 782D (CCC continued the Kind/Code system for the Red IH Cub Cadets produced between 1981 & 1985.
0710 = 1572
Note how the model codes changed with the paint for the 82 series. I suspect the codes for the 482 & 582 were 591 & 592 but I do not have either model nor have ever seen one. Note how the long production of the QL series resulted in multiple model codes for each Cub Cadet model & that some of the model codes I am missing can be easily figured out if they were to surface. Its also interesting that the position of the model code digits changed at the beginning of the QL Series. I suspect that the original intent was to vary the model code according to the way it was equiped just as CCC did after they took over in July 1981. I surmise that some IH bigwig didn't like the idea & it wasn't imlemented till they were their own bosses.
I hope this helps you and please help fill in the blanks as you can and let me know.
Myron
More:
2050001Uxxxxx = an Original with Elec Start
2050002Uxxxxx = an Original with Pull Start
2050011Uxxxxxx = 70 with Elec Start
2050012Uxxxxxx = 70 with Pull Star
2050013Uxxxxxx = 71 with Pull Start
2050014Uxxxxxx = 71 with Elec Start
2050020Uxxxxxx = 100
2050022Uxxxxxx = 102
2050023Uxxxxxx = 122
20500??Uxxxxxx = 123
2050030Uxxxxxx = 72 with Pull Start
2050031Uxxxxxx = 72 with Elec Start
2050032Uxxxxxx = 104
2050033Uxxxxxx = 105
2050034Uxxxxxx = 124
2050035Uxxxxxx = 125
36 & up are listed every where....The above was extracted from IH PL-44s. I'm missing the one from late 1966 or early 1967 with the 123 in it. If you find it please let me know...
[End Quote MB]