SP C-628 page: Switcher renumbering
Heavy Switcher Renumbering:
In 1972-1974, the SP began a program to reassign its six motor ALCO road engines to heavy switchers. Some were assigned to West Colton yard in California, some were assigned to Englewood Yard in Houston, TX and some were assigned to bridge pull service in Avondale, LA. All but two units were done, those two became heavy yard slugs assigned to work with SD38-2's at West Colton yard.
| Switcher number | 1965 number | original number |
| SP 3110 | SP 7104 | SP 4845 |
| SP 3111 | SP 7106 | SP 4847 |
| SP 3112 | SP 7110 | SP 4851 |
| SP 3113 | SP 7113 | SP 4854 |
| SP 3114 | SP 7116 | SP 4857 |
| SP 3115 | SP 7101 | SP 4871 |
| SP 3116 | SP 7125 | SP 4866 |
| SP 3117 | SP 7102 | SP 4872 |
| SP 3118 | SP 7111 | SP 4852 |
| SP 3119 | SP 7114 | SP 4855 |
| SP 3120 | SP 7124 | SP 4865 |
| SP 3121 | SP 7109 | SP 4850 |
| SP 3122 | SP 7105 | SP 4846 |
| SP 3123 | SP 7123 | SP 4864 |
| SP 3124 | SP 7108 | SP 4849 |
| SP 3125 | SP 7117 | SP 4858 |
| SP 3126 | SP 7100 | SP 4870 |
| SP 3127 | SP 7118 | SP 4859 |
| SP 3128 | SP 7103 | SP 4873 |
| SP 3129 | SP 7120 | SP 4861 |
| SP 3130 | SP 7107 | SP 4848 |
| SP 3131 | SP 7112 | SP 4853 |
| SP 3132 | SP 7119 | SP 4860 |
| SP 3133 | SP 7122 | SP 4863 |
| SP 3134 | SP 7126 | SP 4867 |
| SP 3135 | SP 7127 | SP 4868 |
| SP 3136 | SP 7128 | SP 4869 |