Trying to find the right replacement plug from the old NGK-A-7F

Hi,

Looking for some help on Spark Plugs...

I have a old project car, had the engine built some 20yr ago and looking to check a few things and make sure all is running as expected. (even thou car power output very poor for engine)

460 (not identified the block yet)
TRW .30 Forged Popup Pistons
Solid Cam / Roller Rockers (no idea anymore on the cam spec)
Heads from what I could recall had been opened up and larger valves
Eddy Performer Manifold
Holley 850 annular discharge with ROB-E85 Conversion kit (because of the high compression)
MSG 6AL / MSD Blaster 2 Coil / Bosch Dist. with hall effect sensor and external module thingi to trigger the msd / MSD HELI-CORE Solid Suppression Wires

I removed all Spark Plugs NGK- A-7F  (18mm Tapered seat) to check the plugs & carried out some checks from Leads and also the resistance of the plug (if any) from the post to the electrode if any resistance.

All Plugs the plugs apart from #8 returned on the Multimeter set to 200 Ohms between .5 & .8     Plug #8 returned NO VALUE at all (check number of times and even slight clean with some wet and dry on the electrode to make sure connection was good)

Doing number of searches and even calling NGK support today , they could NOT find the plug NGK A-7F in the system and was told to use replacement plus NGK- A7FS  (2976)
(Tried to post picture, but getting msg "Uploaded file is not valid: exceeded attachment maxsize (0 kB)."

Doing more searches, other websites appear to be running all sort of different plugs but the main difference from what I can see is the my current plugs NGK-A-7F and the A7FS are Projection: Non-Projected and alot of other plugs have a Projected Electrode

I have NO IDEA why the plug we used at the time or could it have been just what around I have no idea ?

Anyone got experience with this type of setup - The forged pistons L-2443 TRW with Sparkplugs ? I dont want to use Projected Electrode and find the pistons hitting them ?

Replacement PLUG suggested to use from NGK ?
NGK A7FS
Thread Size: 18mm (11/16")
Hex Size: 25.4mm (1")
Reach: 10.9mm (7/16")
Gap: 0.9mm (0.04")
Thread Pitch: 1.5mm (1/16")
Height Standard: ISO
Centre Electrode:
Type: Standard
Material: Nickel
Size: 2.5mm (1/8")
Projection: Non-Projected
Ground Electrode:
Type: Standard
Material: Nickel
Electrode Count: 1

For that type spark plug, I use the 13/16" hex, Accel #0375.  Summit is the easiest place to get them.

thanks for the reply rmcomprandy...

Looks like Summit & Accel are out of stock on them.... Will continue to look, and understand if the heat range is same as the A-7F plug.
(also have to keep in mind the cost for delivery to AUS, may have to buy a few things to make it worth while...)

thanks
Rob

Autolite racing AR-33 I think.

Use Motorcraft/Autolite   BTF1