I'm building a motor for my mud truck and I need at least 15 inches of vacuum at 800 rpm for tech in. The motor consist of 781 heads with the bigger valves, 9.5-1 compression. Bored .030 over. I'm either going to run a performer or a performer rpm intake. I was wondering if any of you guys have a build close to this with the xe268 cam in it. The main question is what amount of vacuum can you pull with this cam. This is a pretty big deal I don't want to put the motor in and then not pull enough vacuum. Then I have to bump up a class or put a different cam in it. I would appreciate it if one of you guys could check the vacuum on one of your hot rods and give me some feedback. Thanks