318 cam and intake suggestions

I would call Ken at Oregon cam grinding. He's old and has been doing this for a long time and actually Grinds the cams. HeHe m be able to recommend something that would allow you to use your stock Springs. On the cheap I would recommend any streetmaster 318 or Holley performance dual-plane intake you can find. Edelbrock 600 carburetor or 600 Holley. You will definitely need a new timing chain and gears. $25 cheap, $50 very good, 75+ great, at least go very good...
I'm interested in the cam grinding process. How can they take a small cam like a stock 318 and grind It to make it bigger?( higher lift) do they weld to the lobes and add material or something?? Sorry if this is a stupid question but i really dont know and i really want to know lol.