I have a stock 200 with the small log head. My only mods are dual outlet headers with an appropriate exhaust, duraspark ignition and...a weber 38/38. This carb works wonderfully straight out of the box on this engine (this one was packaged for a jeep). GET IT, YOU WILL LOVE IT. It is waaaaay better than the autolite 1101 in terms of power and much better than any of the many weber 32/36 I've worked on on various cars (MGB, Beetle, Datsun 510). As a point of reference, these mods shaved about five seconds off of my 0-60 times (granted the engine wasn't running well before hand)
It has a rock solid idle, pulls strong right off the line, and upped my highway cruising speed by 10mph. And when I finally bolt on my heavily modified M head I'm sure it will really cook. A versatile carb.
Notes: I was talked into getting a carter electric pump ($75), Holley fuel pressure regulator ($30), and various bits of plumbing (the nickle and dime that kill you in the long run) to solve rough running problems early in the installation. Turned out I had a bad coil. I believe this carb will operate just fine with the stock mechanical fule pump if a Holley fuel pressure regulator is used. Try it like that, set the pressure to about 3 psi (you will need to buy a guage and mount it to the extra outlet on the regulator). If you can maintain a consistent pressure with the mechanical pump you just saved yourself $70 - $100.