[Sirrotica]

One other thing that I thought of that can cause revision, a clogged exhaust, or catalytic convertor. I have no idea if your cat is still in place, or not, but there is a slight possibility that you have a clogged catalytic convertor. Likely not that it would happen all at once just after a cam change, but a remote possibility.

If you suspect this, loosening the crossover pipe at the exhaust manifolds will confirm your suspicion. You don't need to remove the pipes, just lower them until they leak, and test it.

I just wanted to cover that possibility, even though it's not high up on the things I would check. I have found a handful of times that somehow the exhaust gets restricted internally, causing this same symptom.