I have done some extensive reading here - and at this point I see a lot of removal to get to the opti. But it does seem to be mostly "plug and chug" unbolting and disconnecting - not much rocket science.
One thing I am unclear on is the "opti seal". There seems to be a seal where the opti mounts to the motor. I see there is one sold - but I can't really see anyone mentioning replacing it here when they do their opti. Is that something that I do also - if so, does someone have a part number?
BTW - following advise here , I will be doing the water pump also - and I welcome any ideas or heads up on that too.

 

I've done 4 opti's. I must say it is not a fun job. Drain all coolant and block Rt/ Left sides before removal of the WP. The Opti seal can be had @ Summit racing. Felpro sells a complete gasket/ seal kit for the front cover of an LT1 and includes the 3 seals (hub/ opti/ WP drive). The seal can be extracted from the timing cover front. I have also dissected opti completely and rebuilt. If you run a high energy ignition (like MSD etc.) I reccomend to use a rivet on the plastic rotor to retain the brass spark contact. My experience has been that the sonic welded plastic button can melt and cause massive damage. Hope this helps. B.

 

The worst part of the job is scraping the water pump gasket surface clean. Other than that its a straightforward remove and replace project.
As far as the seal, it is for the shaft that comes out of the timing cover that drives the opti. The trick is to not damage the new one on the shoulder of the shaft when you install it. I use a cap from a bottle of gear lube (they are cone shaped to slide the seal onto the shaft and fit just right over the end of the shaft) to get the seal on without tearing it. And be sure that the opti is aligned with the shaft when you push it on. There is a filled gap between 2 of the splines on the shaft that must align with the hole in the opti. If you have to force it, it's not aligned right.

 

What exactly am I dealing with - is the seal similar to a wheel bearing grease seal or is it all rubber?

 

It's like a crank seal. Metal outer, rubber lip inner.