can i install it with the distributor on?

I just dot the distributor base and block both with a black sharpie marker.
Without a coil on the intake in the way I can pull my distributor in about 90 seconds, and the same going back it.

One little trick I use that I don't see other people doing is that I have a .020 Oring around the base of the distributor where it meets the block instead of those stupid leaky paper gaskets or the OEM oring. (that always leaks)
Dry as a bone back there, even though I leave the distributor just slightly loose so it can be turned by hand if I want when a big elevation change happens.