318 idles rough and stumbles bad on acceleration

Before you do ANYTHING else count the turns it takes to bottom out the mixture screws then take them out.
Shoot a little WD40 or similar into the idle jet holes and shoot them with compressed air.
Put the idle screws back in all the way and them back them out the amount of turns they were.
This sounds like a classic case of a dirty idle circuit.

Do it or don't, your choice obviously but you might fix it in ten minuets and it doesn't hurt to blow those out once in awhile anyway.
The WD40 just gives substance to the air and carries more junk out.