What las I need

I have a 511" with Eddy RPM head. The cam card has .016 in. and .018ex. what should I set them at.

Try .010 and .012 cold (.006 tighter cold)and then check them with the motor hot to see how much they end up at, adjust accordingly

so it is tighter with the aluminum heads. thanks Cab It is a street roller cam.

Alum heads grow more than a iron head so you
gap them tighter.. myself I use .004 as a
growth factor.. try .004 -.006 cold then check
them when hot.. you only need to check a couple
EDIT
I was running E-85 so the temp didnt get as high
as a normal gas burner... just check your hot lash

Thanks Mike, so I am looking for .016 &..018 hot right?

Thats good with those numbers.. I usually run
a bit on the tight size but you have a tight
lash cam already