What would cause a front tranny seal to blow?

Scott, it's possible the fluid level is too high and leaking out the vent when hot, and you may not have a problem otherwise.

It's ok to run a pint or two low on these.

Check fluid level in park and neutral, and use which ever reading is lowest.

If it's on the stick when cold (just at or below cold), you're good.

What's your fluid temp? In the traps? Cooler? Five back to back runs and the fluid will raise, if overfilled, could leak out vent.

HTH's