I've got a friend that is having a 289 built with a 294S and 10.5:1 compression at Superior Automotive in So Cal. The same engine has a very rare dual quad holley carb'd manifold that was a dealer option back in the 60s...the only one i've every seen. Should be an interesting motor.
The 289 is an amazing engine and can take a lot of RPM's in stock form. Look for a cam with lots of duration and limit the lift to no more than the .525 area and think about using a solid cam which will add additional power but has a little more "give" than a roller. Breathing is a problem so consider after market heads that flow on the exhaust side well. Keep the carb under 650 CFM as it is better to be a little under than over.
If your looking for headers I have a set of tri-y headers that were bead blasted and coated with a high temp coating. If you want you can have them for $50 plus shipping. Let me know
I've got a friend that is having a 289 built with a 294S and 10.5:1 compression at Superior Automotive in So Cal. The same engine has a very rare dual quad holley carb'd manifold that was a dealer option back in the 60s...the only one i've every seen. Should be an interesting motor.
The dual quad intake isn't as rare as you'd think. I"ve seen several on ebay, and Mustangs Unlimited sells the setup complete with carbs over the counter.
If I were you I would just drive the car around with the 289 while you build up a 351w. The 351 shouldn't cost you very much for a good core. Then you can just swap the motors and sell your 289 to someone else and get back the money you spent for the 351. Or you could save the 289 for your next project.
Also you said you were going to do it right the first time so that means you HAVE to have the 351. Otherwise you will regret it later
The 2X4 intake, that I saw in a Mustangs Unlimited catalog is a repro of the Holley flanged intake not the Edelbrock one. Part # for it is C6ZZ-9424-AR, list's for $350 W/O carbs. It would work well with 2 390 cfm Holleys on it. I also thought of using the Edelbrock 2X4 with carb adapters and two 350 Holley 2bbls on it. Be one way to avoid messing with the Edelbrock carbs. I would like to try one on my 89 Ranger's 302, but I don't think the rear carb or air cleaner will clear the firewall.