rough idle and sputtering

I have a 62' C10 w/ a 396 BB Chevy. I recently had to have my lifters replaced. After I got it back from the shop I noticed that it idles rough and sputters when I try to take off. I just purchased the truck about 2 months ago and still don't know all the ins and outs. A friend told me that when the mechanic reassembled the distributor and set the timing that because of the cam setting it by a timing light might not work. He said that I may need to set it but sound? Any suggestions???