Buying new heads .. angled or straight spark plugs?

[KALL64]

I have a 66 and i'm building a 355 for it and getting ready for new afr heads , just wondering what works best for headers ,angled or straight plugs? Thanks

[RustyPile]

It all depends on what you're wanting from the engine. Are you looking for every "ounce" of HP/torque the engine can possibly produce, or just looking for something that looks cool??. Choosing straight plugs or angled ones has nothing to do with header compatibility.. Angling the plug coupled with proper indexing of the tip makes for better flame travel during the combustion process.. As for header choice, there are headers that will clear angled plugs better than straight ones.. And --- there are also headers that will clear straight plugs better than angled ones. Some plug manufacturers even offer a "shorty" plug for additional header clearance.. Carefully choosing a header will give good results (clearance) with either plug choice...