Spark Knock

I have a 1994 Dodge Dakota with the V6 motor, it is standard shift and has about 150 K miles on it.

Here's the problem, It has a spark knock. This isn't an all the time problem but is annoying. It generally happenes when climbing a hill or accelerating. We have changed the plugs and wires. My mechanic suggested running high test gas which helps but doesn't always cure the problem (and is expensive).

Any suggestions?
Thanks in advance

There is a spark plug wire relocating kit from dodge It helped on mine still does it some Mine is a 5.2L