Do I need to replace cranks after newly installed pedals torqued out along with some threads in my crank? I must have crossed threads like an idiot when I installed pedals for my new SPD cleats. After several miles of riding (~100-200 m), I suddenly got this inexplicable rolly, bumpy motion in my foot. The pedal looked skewed out of the crank arm. I removed it with my pedal wrench. Out came several rings of crank thread material. The pedal is fine. 

The previous pedals that I removed were aluminum platforms and needed a dousing of degreaser and hot water to come unstuck. 

I could probably screw the pedal back in with the remaining thread in the crank arm. Is this downright stupid to do?

EDIT: Some pictures and specs for further review

The pedal is a standard SPD Shimano road. I don't have the specific model number, I lost the box.


The crankset is an Omega FS6. It came prepackaged with my bike which was a rebuild. The former aluminum pedals were locked in there like a nightmare. The bike mechanic used thread sealant. Once I wrenched them off, I tried my best to clear out any offending sealant that remained in the threads.
Your cranks are pretty much toast, and even if you try to fix them, you'll always be suspicious of them and won't be able to ride hard without worry. 

Toss them in the trash and get new ones, and be more thorough when reinstalling your pedals.