Is there any harm (or benefit) from using synthetic transmission fluid in a 700r4?

 

which synthetic?

Most successful builders I have talked to hate M1 for this tranny but are fine with Amsoil, then again formulas change.

Might I throw out Dexron VI as a consideration? I believe the requirements basically mean they are all at least semisynthetic.

 

I use amsoil. Lowers trans temps and makes shifts faster. Can see it easily on newer trans with scan tool