Hi-Po 289 exhaust manifolds....?

[jim2f]

I am working on my 65 coupe. Upgrading to Holley Fuel Injection and a few other mods. The 289 in my car is a 2v, with the added performance of the new intake and fuel injection the engine will need better flowing exhaust. The rest of the engine is stock except for electronic ignition. I am undecided as to install headers or the cast iron hi-po exhaust manifolds. I like the retro look of the cast iron but not sure of how well they work. Has anybody installed the Hi-Po exhaust manifolds and how will they effect torque and horsepower.

While i have the intake off I thought about removing the heads to match the intake ports and doing a little polishing on the runners. Anybody had any luck with this.