Yes, your intake will bolt right on considering the Windsor heads and the later 289/302 heads were pretty much identical except for the head bolt sizes.
As far as push rod length, you won't really know unless you go in and check it with an adjustable push rod to make sure the geometry is correct. This will vary depending on what valve train you are using.
As soon as you deck the block, surface the heads, change a cam or lifters, swap out rockers or anything that can alter the valve train, you should always check your geometry.
You have leeway if you are using stock rocker arms because they have a long, flat surface area to ride along the tip of the valve, but as soon as you go with roller rockers, that contact point becomes very small and you want to MAKE SURE the rocker arm is centered over that valve tip.
If your push rods are too long, it'll push the rocker off the outer edge of the valve tip. If they are too short, it'll do the same thing on the inside edge of the valve tip. Of course you have a little leeway, but not too much, so you want to be sure before you go buying any push rods. Better to find out now while you are doing it than later-on the hard way and have to go back and re-do it again