[Bob Kontak]

When you have the fan out, or at least tilted back, check on top of your cylinders for debris and remove.

The job is tedious but not complex. One thing that I did not know - and slowed down my progress - is that the shroud around the fan fits on a peg in the engine case. The shroud has a slot - not a hole - and can be moved front to back on the peg. I pictured a hole only in the shroud and burned a lot of time trying to find that sweet spot where the shroud was fixed in all directions.
Also just replaced a Valeo in an 89 turbo and there was a torx type fastener that I did not anticipate. I cheated with an allen wrench that worked in the the torx fastener but that ain't the way to do it right.

No idea on if one regulator is better than the other. I have used Valeo with success.