65Vert

Okay. so i seems like the advise for a 289 is to go for a dual plane intake manifold.

what model 4 bbl carbs would you go for? for an old stang is EGR even needed? will it be bad or have no effect or even be good?

what models and types around the 500 to 600 cfm range come recommended based on experience. is it advisable to go 2nd hand or brand new to minimize need for re-build?

cost is an issue so I dont want to spend on something expensive only to realise i cant use it or it wont really help.

also what mods would go well with a 600 cfm dual plane set-up. Cams? etc?

atomsk680

600 is quite a bit for a 289

65Vert

How about 500cfm?

FuzzyDiceRule

The edelbrock RPM Air-gap is a dual plane, and is recommended with the edelbrock thunder series, which comes in 500 cfm.

Soaring

You will find a bunch of differing opinions on this board regarding intake manifolds and carburetors for stock 289 A code engines. There is no one "Right" way to go, just different opinions. Do some research into the Weiand Stealth dual plane intakes, and the Motorcraft 4100 1.08 carburetors. Also, look into the Edelbrock system with the Edelbrock RPM dual plane intake and the Edelbrock carb. I have never had success with Holley carburetors, but others swear by them. Yeah, I know.....it gets confusing.
Other upgrades you may want to consider would be a mild cam and headers if you don't already have them. The idea is to get that engine to breathe better. Dual exhaust system is also a power adding mod. Also, upgrading to electronic ignition is a good idea. Pertronix makes a good system that is inexpensive and very easy to install.
Good Luck with it whichever way you go.

Colorado_Mustang

A 500 Holley would work great. I've had Edel and Holley, and although the Edel was easier to tune, the power/economy difference is night and day with the Holley being much, much better in both arenas...and that's converting to a double pumper which is not known for fuel economy.

I'll second Soaring's comments about upgrading other engine components, though we'll differ in the what's. The first thing I'd do is have screw in rocker arm studs installed if you keep your stock heads. The stock push in studs push out over time, changing the max lift and altering the timing events of the cam. This isn't an issue if you go to an set of aftermarket heads, as I haven't seen one that didn't have screw in studs. At that time, I'd be getting an electronic ignition. I like the MSD 6AL, which many will say is overkill. It's a good start in my book. You can add several modules to the box to tailor it to your needs. You can even change the timing from your driver's seat. A cam in the .480-.490 lift range with 225* @.050 will wake up that little 289 without a large change in the idle quality.