It wouldnt hurt any, i just picked up a complete refurb head off Ebay for $250 including shipping, valves were redone the whole shabang, i just needed to add the front seal., i would do a valve job on any head i put on if i plan on running the car for more then 50K with the head i put on, I believe it cost's more to have your own head machined so if you can find a deal like i did go for it. i typicly dont have the cash to hand over for head machining and have done just normall head swap's until i picked up that head from ebay, i have yet to ever have any problem's but as always the recomendations for sanding and machining have good merit as you could increase your chance of having a problem if you dont, its all up to the person doing it and if you can afforde to what is recomended.