Well, before you get too far, make sure you cc the head before you mill it. You'll reduce the chamber volume by roughly 2cc per 0.010" of mill (give or take). If you mill it 0.075" and it's already been milled 0.020" by the PO, you're going to run into issues with thin walls on the head and run the risk of it blowing up. Since you're already going to be having the head worked on, consider running 1.75" intake and 1.50" exhaust valves. I don't know when Ford went to the larger intake, but I don't know that they ever bumped up the exhaust. Measure what you've got and go from there.
You should still be able to use the pushrods but it's not very expensive to get an adjustable pushrod and measure to make sure. I ended up having to get quite a bit shorter pushrods than "normal" for my adjustable rocker arm setup. I would recommend measuring then calling Matt at Vintage Inlines to see what he has in stock.
While the head is off, go ahead and measure the piston shortfall. It'll let you know where you're going to end up from a compression ratio standpoint. This is also the perfect time to put in a new cam, depending on what your budget is. If nothing else, I recommend the adjustable, dual chain. mine fit perfect. I installed my cam with 4* of advance.