O.K., I began dropping my rat in the Nova this weekend. I had a 396 before and bolted my Hooker Headers on with no problems. After finding out the block was cracked, I started building a 454 and had the heads worked on with bigger valves, new springs, etc. Now, I have been trying to bolt on the same headers on the same heads, and they wont go. I tried moving them, bolting from under the car, lifting the engine a bit, and nothing. The only thing I have different, is now they have header wrap, and also I used ARP Head Studs this time around. I tried to look to see if they are hitting the head studs and not allowing the bolt to go in, but can't get a good view. Has anyone ran into this with Head Studs? I was thinking about grinding some meat off of the bottom part of the header to make sure they clear the studs, but before I do, I wanted to run my problem through the experts here. Maybe I am missing something? Help.