what temperature would you mash a California common at? 150F or 154F?

I'm planning on using Jamil's recipe but the recipe in Fred Bonjour's site says 154F and the recipe in the brewing classic styles book says 150F. I'm leaning toward 150F to get a nice dry beer like Anchor Steam. Maybe I'm over thinking it or guys would like to give opinions on how different the beers would be at the different temps.

Recipe for 6 gallons:

2-row 9 lbs
munich 2 lbs
40L 1 lb
Victory .5 lb
pale chocolate .13 lb

with that full pound of crystal malt, plus all that munich, i'd shoot for lower, prob 151ish...

I'd drop Fred a note and ask his opinion on the mash temp. He may have revised it.

alrighty then. I'll keep it on the cool side and see what I get.

how do you know what to mash what at? is there a rule of thumb?

"is there a rule of thumb?"
yes, it should be too hot to put your thumb in it, but you won't know unless you put your thumb in it

low end 148 degrees high end 158 degrees
lower end produces more alcohol, higher end produces more sweetness

read this chapter: http://www.howtobrew.com/section3/chapter16-2.html
and here's a chart: http://www.brewsupplies.com/mashing_temperatures.htm
and Google "Mash Temperature"