Paul   The retaining plate for the ring gear used on 2.85 redrive shows
8 flat head machine screws to hold it in place do you have any idea what
size ?  I have my housing machined so all will fit and  I am ready to
drill and tap housing to hold retaining plate    Thanks  Keith

No I don't but my guess is 1/4 28 would do.
What is the bolt circle diameter?
I have the dwg but I'll have to load it into Rhino
and scale it. Looks like there is room for 5/16th.

Paul Lamar