here are some i've found, no doubt there are many more:
con, cot, cop, coo, cool, coot, can, cat, son, sot, sit, sop, sip, sat, sap, pat, past, cast, cost, coat, coast, pot, pan, pants, paint, lint, oil, pint, pant, lean, leant, pent, ten, tent, tan, nit, nip, pin, spin, span, spoon, spit, spot, spat, spite, spate, paste, caste, sec, sac, tic, top, tip, tap, coal, loan, tone, tine, stint, tint, taint, spent, saint, stain, nope, cope, scope, scape, cape, cane, pane, lane, plane, plain, lain, stop, scone, cone, pole, clap, clip, lap, lip, slip, slap, lapse, seal, scale, post, poise, toil, spoil, scalp