Trac Loc limited slip additive, how much?

Hey guys,
I have a brand new trac loc installed on a completely rebuilt 9" with 3.50:1 gears. I plan to use the Ford limited slip additive and standard diff oil 90/140(as recommended by the diff builder). What oil weight are you guys using and how many little bottles of the Ford slip additive do you use?
Its in my 70 with M code warmed up a bit. The car is a weekend cruiser.
Thanks.
Darren

One 4 oz, bottle. 85W-90 oil.

You can buy the 85/90 with the additive already in it. I have used it for 30 years with no problems.

Great, thanks guys!