I actually did the dizzy already last week for the first time and with the manifold on. It was so much easier than people made it out to be.
Just put it at TDC as mentioned on compression stroke, took a photo of the old rotor that was at about 2. The RAE one I just bought does not have a notch but the old bosch one does so I just marked it myself in the same spot like Someguy just said. Only took a couple of goes to get it straight. Wasn't hard to lean over and do it at all but would much easier with the manifold off. I'd still not recommend taking it off just to do it like so many people have said on this forum. Maybe I'm just younger and more flexible than some.
If timing chain isn't bad, can I just chuck a zip tie on it so it stays at the exact same links, chuck the new cam in and slide it back over? I used to do it this was way with my Ford 6s so it made sure it never slipped and dropped down the front case.
One other thing, I'm going to do the valve springs using the rope method cause I cbf buying a compressor and finding an adaptor. Any tips even though I've watched a few youtube vids and it looks fairly simple?
I'm about to head off to buy a spring compressor, balancer removal tool and finally a torque wrench cause I've always need one anyway.
Cheers for the posts.