If I run a Cool Head or a milled stock head at about 215 psi compression, with race fuel, do I need to advance my timing? I've yes and no to this question?

 

You don't have to, but you can get a little extra mid range power if you advance your timing. I have an R that has a similar setup as you do and am running stock timing. It's not too critical, but like I said, you can get a little extra power out of the motor.

I would leave it alone.

 

I run a 330 cylinder with the crank stroked 4mm and 215lbs compression with the timing advanced 3 degrees. It was hard to tell if the advance did anything because I already have a lot of bottom and mid because of the increased stroke but you should feel a difference on a non-stroked motor. Running race gas you won't have a problem. The only thing I see is that the more you advance the timing the harder it is to start when it's cold. Likes to kick back on you.

Jeff