318 backfiring

Them dang ballast resistors I've replaced 2 this year on 2 different vehicles. I'd replace that and the points right off the bat. At least clean up the points eith some fine sand paper real quick. Try it if that dont work pull valve cover tap each valve with brass mallet and try again.
Stuck lifters, I would drip trans fluid down the pushrod and let it set for a few then give em a tap. This worked quite well.