Smokey Yunick invented the projected tip plug--it has been std equip for 40-50 years now?? They are supposed to idle cleaner and better
I have been a hot rod nut and engine guy all my life --I have never had a better plug or better plug company than NGK--quality is unsurpassed--tech line answers phone on first rings and if you give correct info--all ya need is correct compression ratio--fuel type--and the proper thread engagement stuff like always They will put you ON THE MONEY first time if you give correct info Then you order off Ebay with free shipping and no sales tax and get the best for less--I tell this tale again and again but folks fight it and always have other opinions---
Yes Autolite race plugs and Champion race series are good plugs but tech is almost non-existent and price is just stupid compared to NGK on Egay
Just try call NGK tech which you can Google
These are the best quality plugs available Japanese made --superior quality--Amazing tech support--and best price of all the quality units available
Quit fighting City Hall and try em will ya???