.0015 would be fine, 1 and 1/2 thousandths but the other is 15 thousandths
and is out of spec
Find a shop that will work with you and just clean up the warped head and not do
a clear cut pass over the whole surface, most are just too lazy or in too much of a
hurry and don't care about just shaving a 20 off to get it done.
The stock compression is fine for turbo up to about 10 PSI, but you will need forged
pistons if you go over 5 PSI. Now you have to figure out if this head will be serviceable
for turbo use, depending on what they need to shave off to clean it up. You might need
another head and just run this one as a higher compression na head before you do the
turbo build