2.73 rear and Powerglide tranny...that combo doesn't spell performance
Adding the 4 barrel and a fresh valve job won't hurt, but your performance dollars would be better spent on a little more gear [maybe 3.31/3.42]...and if possible a TH350 tranny...should bolt right in where the glide is now.
Those additions will add much more to the equation and enjoyment than a cam swap...once you have those items behind you, then consider other engine mods.
good luck..wilma