i am going to buy a 5spd s20 tranny but it has a welded differential .is that good or not?can i use an automatic tranny differential for this tranny?please i need advice as soon as possible

 

The tires are going to squel real bad around turns when you get on it other than that it will be fine. Welded diffs have been around for years it was big with the older muscle cars that were all about stright line performance. I live for the twistys so it just isnt for me.
No you can't use the diff out of the auto in the manual trans.

 

how do you make the tranny double traction?that is that both tires move at the same time(Posee)