Yeah it should work fine without the kick down hooked up... As far as the downshift problem,the governer is hanging up. A quick easy fix is get it running about 20 mph down the road and very quickly and carefully bump it in and out of park a couple times,(be darned careful to not hit reverse and for sure don't hold it in park). This will rattle the heck out of the governer and usually frees it right up. An old tranny guy showed me this trick years ago after the governer stuck on a fresh build c-4.