This is my personal experience on wakeing up the bone stock 200 / c4 in my 67 Mustang vert .
The car ran great for a slug when I got the car . First thing to realize when you say I want to make it a better cruiseing, running car it IT COST MONEY to get there & for the most part the oem parts don't cut it .
I made a long range plan & started working toward that goal ,not an all out power, tire burning machine just a better car .
First thing I did was install a 2300 Sniper with a 2x1 adaptor on a small log head ,small stock 67 exhaust system, point dist stock eng along with a Msd 6AL ign box .
In all honesty for what most people say they want out of a 200 that is plenty . Instant start up, smooth idle & way more power. Mine ran about 50 in low ,70 in 2nd & still pulling when I hit Drive & was pretty quick about it .
Since then I have moved thru a Dura Spark dist which is a tremendous upgrade to a Holley Hyper Spark . Put a e bay split header with 2 1/4" duals on.
Easy pretty much. Problem free ? Not hardley. Expensive ? You know it . Worth it? Every penny it cost . Run like a v8? Don't be stupid .
But my car was a 6 & I never plan on her being anything but a 6 . The car has had pretty much everything on her modified except the body .
In the beguinning i said i had made a long range plan . This is coming in near future, its all sitting there waiting on me