i am going to pull my heads pretty soon but i was wondering if i take them off do i have to reface them at a machine shop

 

nah, you dont have to.....what are you doing to them?.....when i bent my rod, i wentahead and ported them and got a valve job and the shop checked em and said they were warped just alittle, but should be fine....but for the extra $20 or so i went ahead and had em resurfaced.........i would check them at least

 

Take them to the machine shop and have them check for warping. If warped get them
resurfaced, if not warped then don't bother.

 

^^^ +1 xskylinedx

 

Heads are out of spec if any gap is over .012inches when compared to a perfectly flat surface. Any larger and you should get it machined. If you we're unlucky enough to have a .015 gap on the heads and block there would only be a .010 thickness of gasket keeping the head sealed and that won't have the right amount of compression on the gasket in that spot to seal.