How to know what modifications have been done to 318?

im guessing with a 2 barrel still on it not much has been done to the heads but its really easy to tell if its been gasket matched and worked over. also measure the valves, stock is 1.78 and 1.5. cam is more complicated. you could just measure the lobe and multiply by 1.5 to get valve lift but for duration you need to get your hands on a degree wheel unless someone else has a cheater way to do it. stock bore is 3.91. as for the 360 heads, you would definately have to mill them down unless you already have hi-comp pistons. just measure how far you are in the hole. stock is around .100