1966-FASTBACK

getting down to the nitty gritty on my 331 Stroker which has Edelbrock Performer RPM aluminum heads on it and wondering what plugs it takes and which ones would work best. just picking your guys brains for your experiance.

001mustang

I haven't bought into most spark plug hype; improved HP, mileage, etc.
I have seen platinum plugs last over 150,000 miles on new car.

I've stripped out aluminum threads removing fasteners.
Do your plug threads have steel inserts?
If not I would use great care w/ proper torque and type of anti seize used.

Verify piston does not kiss plug before starting engine.

everett

I put the Bosch platinum/iridium 4 ground strap plugs in and they woke my 4.6 right up

67mustang302

Autolite copper cores. All the other plugs are crap designed to make money. Platinums are for longevity which is why production cars use them, since ignition system is part of smog and is required to last the life of the vehicle....plats mean no need to manufacturers to change plugs under warranty.

001mustang

Wish I could see a few dyno studies supporting hi tech plug HP gains so I don't have to be a doubting thomas.

Jonk67

Autolite 3924 Copper cores here also, going into my 333ci stroker w/AFR 165's.
I agree on the platinums and save them for the new car.
Jon

Iskwezm

Doesnt Edelbrock recommend a Autolite plug mainly for the length and heat range?

tx65coupe

I run these Motorcraft AGSP32C plugs with my Edelbrock heads. Its what Edlebrock recommends.

http://www.mustangsunlimited.com/ite...?T1=AGSP32C+01

Don't get any snake oil plugs like Bosch +4 or E3 etc.

67mustang302

The performance head manufacturers recommend Autolite coppers for....surprise, their performance. Consistent, reliable ignition and heat control.

kalli

well I'm a bit confused now. My heads (probably the same as original poster)
http://www.summitracing.com/parts/EDL-60259

I am using those:
http://www.summitracing.com/parts/FRM-25/

and summit suggests these:
http://www.summitracing.com/parts/FRM-3926/

different reach, different seal.
Are they wrong or am I ??


Kalli