I read with interest the recent postings to Rex Turners question regarding spark plugs. I drive both 66 427/390 and 67 427/435 Vettes as often as I can during the summer months. The 66 goes on long highway driving trips with it's 3:36 rear end and the 67,with it's 4:11 rear,is only locally driven. Summer temperatures here usually run between 60 and 90 degrees but mostly around 75.
The 66 now uses R43XLS....the 67 uses R42XLS and both detonate just a little when hot. Can anyone offer any advice regarding the use of hotter or colder plugs from their previous driving experiences? Any other thoughts would be very welcome. Thanks.
The 66 now uses R43XLS....the 67 uses R42XLS and both detonate just a little when hot. Can anyone offer any advice regarding the use of hotter or colder plugs from their previous driving experiences? Any other thoughts would be very welcome. Thanks.
Comment