Well if you want straight spark plugs for header clearance to use parts you already have...MP "aluminum 452" but I'm not sure if MP even still sells them as most of the product line has been killed off.
i think these are the MP452 heads. it says they are straight plugs and they list a MP part number for cross reference. they are also on clearance... https://www.manciniracing.com/edperpmcyhe9.html
