If you go with a cam, I'd suggest getting the cam package. As G mentioned, the valve springs have to be compatible with the lift of the new cam, and new retainers and keepers are just a good insurance policy!!! The stock components have got to be suffering from a bit of age fatigue by now so new one's would be a good investment.

For the street, the old 390 GT cam and valve train is pretty tough to beat! Lots of the manufacturer's offer cams with specs similar to the stock GT cam. For an intake, if you can find one and don't mind parting with the $$$$, the factory aluminum PI intake is a very nice one, and there is also a good Weiand intake I can never remember the number for, but G always comes up with it for me!!!!!

Only reason I can think the headers wouldn't work on your drop top is there may be some interference problems with the extra bracing on the frames for the convertibles.... Can't say I've ever put headers on a convertible of that era, so I can't say for sure, maybe someone else has some experience with them......

Anyway, FE's can be made to produce a bunch of torque! I have a 428 in my T-Bird that I'm looking forward to getting into sometime this winter!!!!! Good luck with your Galaxie!!!!