I don't see that engine needing a nitro boost. A better solution to running your engine in colder weather is to check the head temp and see how hot (or cold) it's running. A good head temp at the glow plug is around 300 - 350* F. If it is noticeably cooler than this, blocking some of the head fins would help to raise the temp. A cold running engine will not burn fuel efficiently and will run as though it is way too rich.

Jesse