I have a 1983 S series jimmy , I took out the 2.8 and 5spd and stuffed in a 350/700r4 4X4.
I have two problems , my first is the ignition module , the dist is a out of the box malloroy HEI unit ( stand alone )when it was first installed , the truck ran great , snappy response , but that gradually went away , the truck became harder to start , faulty module . Replaced it , with supplied heat transfer grease , and everything is back to normal .
A month goes by and then you can feel the performance is off , the truck is hard to start.
I have tried . New O rated resistance 9ml plug wires
. A/C delco plugs gapped @0.40
. Plumbed in a 4" duct from the air dam up to the engine compartment ( thought maybe excessive heat )
. Tried various ign.modules , all lasting and acting the same
. Truck origanally came with an HEI system so Resistor should not be an issue.
Maybe some one out there has experienced the same