I have a 302 d8ve-6015-a3a block +30 over, and have the eagle B16422MA030 balanced 347 kit, comp cams hydraulic rollercam retro cca-cl31-600-8, procomp 62cc heads and edelbrock proflo 4 injection, What Ratio should i have on the rockerarms, or shoud i go for standard?
Installing a hydraulic roller cam in an older block requires paying attention to a lot of details. First, you will need a distributor that has a gear for a steel hydraulic roller cam. Cast iron flat tappet cams use an iron gear on the distributor, which is not compatible with the steel hydraulic roller. The cheapest way to go, is to buy a replacement distributor for a 1985 mustang, as that was the only year that had had a hydraulic roller cam with a carburetor. You can plug it into whatever ignition you are running. Of course, you can also buy an MSD distributor or something similar... as they have much more easily adjustable ignition advance curves.
You will need a compatible cam thrust plate and timing chain set. Go to the links I posted in the '302 cam thrust plate' thread in the All Ford Techboard.
Make sure the springs match the camshaft, and rocker geometry is correct... or you may destroy things before the first oil change. I won't go into retro cams vs. standard... But you can use standard base circle cams with link bar lifters, and it's a much better setup than using the reduced base circle retro-fit cams. The link bar lifters for use with a standard cam use to be more expensive than standard lifters used with the retro setup. And again, learn to check rocker geometry. I guarantee you will need custom length pushrods, which can be ordered. Your heads will use guide plate, which will require hardened pushrods. You can easily order custom lengths from Smith Brothers, Manton... and even Summit. You won't need anything special other than being hardened and the right length.
As for your original question... Standard ratio rockers will be just fine. Choose a name brand, and resist the cheap, crappy Chinese stuff.