You won't have to pull the heads, but the upper and lower intake, valve covers, harmomic balancer,accessories that are mounted to the timing cover, water pump, radiator (so you'll have room to pull out the cam and replace it) , cooling fan, timing chain and sprockets, lifters, rocker arms, pushrods. That is about what you'll have to pull and replace to do the cam. I'd get a new timing chain and sprockets since you'll be pulling the old set off (unless the chain and sprockets are relatively new)-----Chuck | 
