Engine upgrades

I have a 85 vic and i wanna make it move a little faster.(I know its a heavy car so i can only expect so much outta it at the same time) Right now shes pretty good but since its a 5.0L and I know theres alot of ways to get some more power outta it.

I was thinking of gettin a 4v intake and carb to start off with and then going from 2'' duals to 2.5 or 3''(depending on which is best)

Would it be possible to take the cam out of an 85 stang, and if so is this going to help me much?

If i do these upgrades how is the transmission and rear end going to hold up. I know these mods wont add any serious power but im also taking the age of these components into mind.

Thanks for your feedback