ok, here's where I show just how much I don't know. What is required when changing from 2 barrel to 4 barrel? The intake and carb, of course but, are there any other tuning or internal changes that need to take place? Any info would be greatly appreciated. While I'm posting how do you calculate the cfm for the carb? I'm working on a 1965 2v 289 engine. Thanks!  

I swapped carbs on my 65 289 this past year. I got everything I needed from Pony Carburtors (www.poyycarburtors.com). I went with a 4100 carb and a stock Ford intake,also needed a spacer plate,return spring,some bracket. Go to thier website, the have some good info there. It will explain almost everything. The people on the phone were very helpful also, they made sure I had everything needed (weather I got it from them or else where). Plus they send you great directions on DVD and if thats not enough call them back. The swap took me one Saturday and my biggest concern was getting the distributor back in right. My 65 started right up and I'm very happy with the out come. Check out pony carbs web site.  

Arispoli went the expensive but safe way.  Yes, Pony Carbs is a real safe way to get everything right with the swap, but they are very expensive.  If you want to stick with a basic factory "A" code setup, then yes the Motorcraft 4100 and factory intake is the way to go.  But, you can get those off of Ebay for a fraction of the cost as getting them from Pony Carbs.  

HI
I just fitted a 600 cfm Holley and a performer Edelbrock manifold to my 67 with 289. Instuctions were easy to follow, dvd with carb easy instuctions with manifold. Car performs much better down low and much better mid range. Items were new but priced well. Not sure on fuel consumption yet.

                 John  

I believe the factory 4100 carbs flow in the 480-560 CFM range which is more than enough for a stock 289. Edelbrock bought the Carter AFB carb line line several years ago and the have a nice & decent unit unit for about 250 bucks.  Do not exceed 600CFM with 480 - 560 CFM being the prefered range of carb sizings based on my research into the subject.  

Manifolds are a personal choice the Edelbrock Performer is a nice stock style dual plane while there are a few more Hipo units out there. you wantr a manifold designed to operate in the 1000 up to 5000 rpm range.
You will need need gaskets and silicone sealer for the ends, new bolts are recommended, a new thermostat and housing are a good investment while you have it off,a spacer is not usually necessary with the Edelbrock setup.  

Great information! Thanks to all who responded. I'll respond with the set up I go with once it's in.  

I went all Edelbrock purchased from Jegs. Great price and equipment. '66, 289, Edelbrock RV cam/intake/600cfm carb  

Just curious here as to swapping from 2 to 4 barrel on a straight 6. can it be done? the head is cast with the intake so its all one piece, so no chance of changing the intake. is there an adapter plate?  

As far as I know, you can go from a one barrel carb to a two barrel carb on an I6, but I have not heard of a 4 barrel carb on an I6.  Not to say it can't be done.  Try contacting the folks at http://www.ford6.com  

I'm sure if nobody makes an adaptor plate one could be fashioned but my question is why? I don't think, and I'm no engineer so I could be wrong, there would be any gain by using a 4V on an I6. A stock 289 doesn't want more than 600 CFM so I would guesstimate a 200 wouldn't want more than 400 to 450 CFM. Are there any 450 CFM 4V carbs? Again I'm no expert or engineer but based on my limited knowledge and the fact that there is not an abundance of readily available adaptors I would guess that it is not recommended.  

Holley does make a 390 cfm four barrel carb its part number 0-8007. They also make a 4160 in 450 cfm (#80364). There is also a 1.08 venturi Ford 4100 carb that flows 480 cfm. So there are small 4V carbs out there. I have seen a Holley 4V used on an Australian crossflow head swapped on to a Mustang 200 six. In fact I am thinking of doing one myself some time in the future. There is also rumour of a domestic aluminium head for that six with bigger valves and better flow although I havent yet found that source.
The formula for cfm is
CFM = (cubic inches x Max rpm x volumatric efficiency)divided by 3456


which for a screaming well cammed 200 six is about 295 cfm (with 6000 rpm and 85% volumetric efficiency)

So you can see most two barrel carbs are more then enough for a healthy six.