Which spark plug for M&A aluminum head


Im back!! Maybe for good
I need to know what spark plugs to run for my SII motor. The motor has an old set of M&A aluminum heads on it. I have a set of NGK 4554 plugs will they work?



Im back!! Maybe for good
Here is the info on the plugs I currently have. the NGK 4554
Manufacturer Heat Range 8
Electrode Core Material Copper
Electrode Tip Material Nickel alloy
Insulator Type Non-projected
Spark Plug Thread Size 14mm
Spark Plug Reach 0.750 in.
Spark Plug Seat Style Gasket
Wrench Diameter 5/8 in.
Ground Strap Quantity One
NGK Part Number R5671A-8

I know the thread, reach, and seat are correct. Does the heat range matter??

slamming 6

Drag Master
You will have to read the plugs to know if the heat range is right.Every engine is different the plugs that were in the heads i am doing had NGK TR5's in them.BTW great job on your truck.


Gray Beard Member
As Slamming says, every engine is different.

I'm running NGK 5238 - 9's gapped at 28 on my T/A aluminum headed 109, and they seem like they might be a little cold for the street. Car runs low tens currently.

I have some 5445 - 8s on the shelf and need to try them out. Maybe a tiny bit bigger gap, too. It's finally cooled down in Phoenix.

It's not a Stage 2 engine, so I'm not sure that this info applies in any way, but I figured I would put it out there.

Good luck!
Last edited: