advantages of this combo??

[whitesswj]

I did the raise tire up rotate 20 count shaft technique and figured a little over 37.25 turns on the shaft and that makes a 3.73 rear if i did my research right.

I've got a 3 speed from a 67 inline six and a 350 bored .060 with an edle #1405 on an edle preformer intake.
what kind of MPG or git up and go and other what knot should i get?
any advantages?
any Disadvantages?

thanks sswj