If my installed lever is a 2.9 ratio and the trans is out of my car now is this something I definitely want to change or is the 2.9 fine to stick with (69 R/T stockish 440/727)? IF i should change where do you get these?

Also was going to put a transgo TF2 kit in while the tranny is out if I can gain enough confidence to do so (instructions in the kit are a bit vague/confusing to a novice).