Some Advice Needed

ok so the winter is coming, i'm planning on riding my 490 when the new topend is installed and everything is all hooked up.

i want my engine running rich because it's better to foul a plug then to blow up a motor. its gunna be pretty cold and engine drawing in alot of air.

i have a 430,440,450 main jet.
will i need to use the 450 since winter is coming or is this bike jetted rich enuff at stock 440

i am concearned also about the airscrew and needle adjustments.

how much compensation is needed

stock needle clip position is 3 do i need to adjust 1 or 2 times richer on that?

also any suggestions on the air screw?

i am generally just looking for a safe carb config so that the engine performs okay and does not ping to much and run to hot

also bear in mind that the bike is gunna be .040 or .060 over stock so im guessing that will affect jetting a bit.

im mostly concearned about gettin 1/8-3/4 throttle jetted good, i don't think the bike will see wide open throttle often

i will use stock jetting and check the plug i guess see how that works for a while.
and i use lucas high performance 2 stroke oil at 24:1 is that a good ratio? it ses in the clymer manual to use 24:1