AC/Delco
Is it easier to take off panel between wheels and engine?
Autolite plugs work pretty good but I found Motorcraft plugs to work the best
platinum plugs atleast that's what they come with from the factory
.035 inch........for the ABSOLUTE best power use Autolite AT3 spark plugs. I had 65 327/365hp in 65. Motor Trend did a test on spark plugs using a 389 cu in GTO engine. They gained ten (10) HP by simple change the plugs to Autolite AT3. Good luck.
You have to use platinum-tipped spark plugs ONLY.
NGK laser iridium spark plugs.
the best spark plugs for all ford vehicles are the motorcraft type, which they come from ford.
The best spark plugs are the original equipment plugs that were installed by the manufacturer at the factory. Sometimes you may need to go to a dealer to get the exact plugs.
AC plugs
To change the spark plugs on a Vauxhall Zafira open the hood of the vehicle. The spark plugs will be located on the engine. It is best to used a spark plug removed to unscrew the plugs. They will be connected to a cable. Remove the cable. Replace the plugs with new ones and reattach the cable.
It is best to go with the factory used spark plugs. The factory uses champions.
As for NGK or Denso OEM spark plugs.