Can anyone tell me what the advantage is of angled plugs if any? I have a stock 327 with straight plugs in stock heads. I plan to get some high performance aluminum heads and want to be sure Summit headers the headers I have will still fit.
Thanks for any advice
Steve

Header clearance is one possible advantage.

Jim

There are various reasons now on angle plugs, theory is to move the plug closer to exhaust port. Other reasons were for piston domes that were too high and cut the plug fire off, thus needing slots (fire slot) cut into pistons. No real street advantage , IMO. You do need to order headers that fit your application.
I would open a can of worms on this topic so I will leave it there. If you do a search on this topic here, you will find much information and discussion on it.

cheapie headers are for straight plug only.
Hedman and hooker (many others too) make headers that clear both straight and Angle plugs.

Mild street/strip use, either plug is fine.
Racing engines, angle plugs will show a slight gain.