Live in MN with sub-zero temps.. The truck has been nothing but great; starting instantaneous and going throughout everything I’ve thrown at her.
Recently, I parked her at my friends house and would not start; would crank, but not even ignite gas. Check under carb and gas was in (have recently installed new fuel pump), loosen a spark plug and saw sparks. Still changed the plugs and wires cause I was advised by the previous owner. Worked and got her running again. But it when slowing down or completely stopping it would come very close to stalling then jump back to normal sounds.. Previous owner advised I change the Distributor Cap and Rotor so I did that and sounds better; but now acceleration is worse that ever and budge over 40mpg without feeling like I was flooding the engine..
Any suggestions or pointers?

 

so a couple possible issues ... mine had a similar situation. cleaning my EGR ports and IAC motor helped some, ultimately mine had a internally blown head gasket on #2 and #3 cylinders.
pull the plugs and get a good look down the cylinder at the top of the pistons, if 1 or more look cleaner than the others, you have a head gasket failing.
not the end of the world, about $60 in gaskets and 4-6h work.