Ok, now I'm going to have to go home and pull a header bolt just to see if I spring a leak, because I have never had a leak either...and have never put any sealer on the header bolts....weird....does this only apply to factory heads by chance? The reason I ask is I'm currently using Edelbrock heads with no studs, and come to think of it, all the iron head I used in the past had the studs on the front and rear.....mmmm......I'll definitely have to look when I get home tonight.