Dodge Repair: P0720 and P1391 ODB codes, crank sensor, dodge durango

Question
Hi, Very impressed with the quality of the answers on this site so I figured I would give it a try.  I installed a new long block in a 1998 5.2L Dodge Durango, but after a couple hundred miles, the Check Engine light came on and I get the following 2 codes:
P0720 Trans output speed sensor
P1391 Intermittent Loss of CMP or CKP
Notes:
--When I cleared the codes, they came back within a couple of miles
--The truck runs great.
I would suspect that I might have damaged some cables rather than both sensors failing at the same time, but was hoping for some feedback or suggestions from the experts!

BTW, just tonight I noticed that the temperature indicator does not work.

Thanks!
Randy

Answer
brand new long block  or junk yard one?
did u reinstall the crank sensor when unbolted up the tranny  or not?
the code is for cam OR crank does not say which one.  
if u have a wire harness  then I would go back and relook at a harness pinched or something like that as well.