Are you using a cure? If so it should last as long as any other cured meat!
It should not take 8 hrs. in a dehydrator, I do mine in about 3-5 hrs depending on which machine I use as one is a bit hotter than the other! turn it about half way through the cooking, blot the melted fat off the top of the strips once or twice.... watch it closely after about 3 hrs because I have learned that it goes from edible to shoe leather quite quickly LOL!!!! Don't for get to add a bit of liquid smoke to your meat......one more thing I add a bit of water when i'm mixing the meat it helps in distributing the spices and makes it flow out of the gun better