I am considering a little experimentation with the single cell lipo thing in a 12th scale. I want to run a lipo receiver pack without a BEC/regulator. Will the electronics be OK on the added voltage? I run a Tekin RS, Spektrum micro receiver, and JR z3550 servo.

Any help would kick ass.

Yup, you should be good.. the Spektrum Rx can take it no problem, and the guy heading the 3.7V 12th scale testing is using what looks like a JR servo like yours..

Check out this post/thread.. http://www.rctech.net/forum/4893629-post230.html