well im just trying to get more pep from a stop I just had the 200 rebuilt with a modified cam and compression I have no idea what they did since im not a mechanic by trade. I took it to a very reputable rebuild and installation shop in San Diego. I definitely trust there work. 2" exhaust I believe no header modificatication and yes 1 barrel stock with pertronix. I think I need to start with a carb upgrade and do something with the ignition.???
That’s good that you have a good shop, who rebuilt the engine to refer to. Where you go from here depends a bit on what the rebuild consisted of; especially the camshaft they chose. Did they provide you with a build sheet for the engine? You kinda want to have the card that came with the camshaft to figure out how much it was hopped up. It would be good to know the compression ratio as well but they may not have done those calculations.
The aftermarket HEI distributor I chose looks similar to the size of the original distributor and it came with a separate coil. It is fully adjustable for amount of vacuum advance (Allen key in vacuum diaphragm) and amount of mechanical advance and where that comes on (using springs and bushings). Out of the box, it’s a pretty good drop in and run unit. It comes with 10 degrees vacuum advance and I think it’s 14 degrees of mechanical which comes on somewhere between 1500-2000 RPM. All in around 3000 RPM (if I recall correctly). I bought it from an EBay Seller called SwapMeetParts. Many people here use the Ford Duraspark II electronic ignition on their 200’s and swear by them.
I’ve had really good results from the Redline/Clifford Performance Weber carburetor kit I installed. I chose the 38/38 which is a bit of a hot rod carb. It can guzzle fuel because both 38mm barrels are in play synchronously. They have a 32/36 version which is progressive; most driving around is on 32mm barrel and the 36mm barrel comes into play when you put your foot into it. I can confidently recommend them. Unbolting the factory carb and installing the Weber on the adapter it comes with is pretty much plug and play. The only trick part is that you need to figure out how to link the factory gas pedal linkage to the carb. Here’s how I did mine. I heated the throttle pedal linkage and bent it up so that it pulls the throttle shaft pivot point up and back. It works great. I’ve got my throttle return spring to a header stud.
EDIT: Get a phenolic spacer to install between the carb and the adapter. It will prevent the carb from taking all of the engine heat and in my experience, you’ll be able to get better fuel economy.
The next piece of the puzzle will be getting the timing right. The factory suggested timing won’t be optimal with a modified engine. If the camshaft has a different grind from factory or adds a bit of a bump to performance, you’ll need more timing to take advantage of it. I spent some time getting my timing right. On a stock 200 in a 1966 Mustang with manual transmission, I think the manual says +6 degrees before top dead centre. With my engine, right now, it’s happiest with +14 degrees initial advance before top dead centre.
Further performance mods would be to work the head a bit or get a large log from the late 70’s to rework for more compression and bigger flow. You will need adjustable rockers though. The large log head comes with bigger intake valves and you can put in larger exhaust valves. You can also machine the larger log intake to bolt the bigger 2 barrel carb directly to the intake log, improving flow dramatically. While you’re at it, the original valve springs are light tension and after 60 years of service they’re going to be weaker. Stiffer springs, within reason will allow you to build power higher in the rev range. People use 302 or 289 springs or your camshaft manufacturer can recommend the correct springs for that camshaft.