Hey Cobras4life,
Be sure to use the correct pushrods and valve springs with your new cam. Also make sure you have the correct distributor gear (material) and it is installed accurately on the distributor shaft.
Aside from that, the manifold is way taller than the stock Cobra air scoop will accommodate. I switched to an Edelbrock Torker II which is the lowest manifold available. I still had to raise the scoop a bit to get an air cleaner with adequate flow capacity to fit - YMMV.
Mine now has almost 13K with no problems - still going
strong 
Tom