OK, you're begging for replies.
You say you're a newbie.
STICK WITH STOCK!!!
Until you're consistantly in the A, stick with stock. If your track only averages 15 or fewer entries, stick with stock until you consistantly finish in the top 3.
Running mod at club races just introduces additional problems. Much more motor maintainance. Motor more expensive. Better drivers -- harder to win. Need better batteries, and you'll replace them more often. You'll crash more often, and that costs $$$ and reduces practice time.
I run in the novice class myself. My home track (CRCRC) routinely has 15 - 20 entries in novice every week. Stock truck draws another 25 - 40, so I won't move up to stock until I'm consistantly in the top three in novice.
I use a blue-top paradox rebuildable motor. It's got plenty of torque, the truck is faster than I am, and it's cheap. Until I can drive that motor well, there's no point in spending 10 cents on more motor. All it will do is cause me to wreck more often and waste time & money. When you're a newbie, the most important thing is more time on the drivers' stand. Get reliable simple equipment and practice like crazy.
Engineering Without Fear