318LA build

If rebuilding you can make measurements to find out and make any necessary mods to fit whatever cam you want.

What you should be finding out what cams are gonna suit your build and if they require you to do mods to run them piston to valve and or retainer clearance etc.. Then you could decide different cam specs and or make the mods.

But unless your building some crazy cammed 318 build with stock heads shouldn't need to do much for the average 318 type cam.