• Hello there guest and Welcome to The #1 Classic Mustang forum!
    To gain full access you must Register. Registration is free and it takes only a few moments to complete.
    Already a member? Login here then!

Sparkplug Choice?

mrgem

Member
I recently had a 331 built by a local machinist using a 66 289 block for a project I am working on. The car has 10.5:1 pistons and Roush (World Products) iron heads. The machinist fit a set of old used plugs in the heads -- just to fill the holes, and I didn't bother to ask him what I should replace them with when I drop the engine in the car.

I can certainly call him and ask what he recomends for plugs, but I was wondering what this group feels are appropriate and a good choice for spark plugs.

The car will be a sunny-day driver with one or two runs down a drag strip every year.
 
Autolite coppers are more than adequate. I believe they're 104's for those heads, but I'm not 100% sure.
 
Back
Top