My GSR head is at the machine shop and they told me that the stock surface is perfectly fine from the factory with no warping or dings. how much do you think i need to surface off? precise calculation.

and he said the exhaust valve guides are out of round, do I have to replace them? what are the consequences if i don't?

 

bump

 

since you have the head at the shop......and even though they say the surface is flat you should have them skim just a little off to make a nice clean surface just to be safe.

as for the guides......if they really are out of round and you do not replace them chances are you will wear out the valve stem seals faster than normal.

 

well i decided to have him replace the guides and he said he was going to resurface .005 off. thanks for all the help