[Bruce Edwards]

When you pull the site plugs the fuel should be right at the edge of the hole. If you bounce the car some should leak out.
6.5 on the valve would be Ok for a setting of 13 to 14 on the engine at idle. I would check that first.
If you are in that area then go to smaller jets. The factory settings sound a lot closer to what I would see for a 351 to 400 ci engine and would have been a good starting point.
Remember that the total jet size will only come into play at full throttle. The idea is to get the best balance between full throttle and cruise mix.
This is why all the new cars are fuel injected. Much easier for the computer to control the mix over different loads and temps that a carb. With a carb you have to do your best to get a happy middle ground.
Have fun and do not let it scare you. Do one thing at a time and check it after every change. The big thing is to give the engine time to adjust to the new settings. So drive it for effect don't go by the way it sounds.
If you have a plug cleaner I would clean them before every change to see how you are doing or buy stock in the plug maker you like best and buy a case!
Tuning can be a real pain but if it is done right it can be a real kick when you find that sweet spot.