Timing and Carbing

Can somebody out there shed some light on my Apche? I and trying to time and carburate my truck properly, What are the steps? What must I do first? I just installed a new 350 with a edelbrock intake and carb( all new). Also I have a MSD ignition coil and 6A ignition box. Can some one help??? By the way the 3rd gear on my th350 waht gives. I've been told to change the modulator, Can this be it?

Ramon

well the manuals that came with your parts might be a first step if you have them. How do you have it setup now? how does it run? More info would be nice