I'm still going to do the rebuild but as I have exclaimed many times that my 350 in my 70 Bird was running quite rough. Well maybe I found the problem and see if yall think this is why too. I was looking at my engine and noticed my down shift cable was broken and I found out from someone today the cable actually just doesn't shift the gears down but has another purpose to control pressure in the fluid in the valve body... which may cause the engine to not run well with it off or in my case broken. So can this be the mysterious cause why my motor will not run well or just suddenly die???  

I don't think that would do it at all mine has been unhooked for a few years now and it does not run any different at all.  

David, I went back and re-read your reader's ride profile, you say you have an edelbrock carb on the stock intake. If this is true we may have found your problem. I don't know if you have an adapter plate under the carb or if it is bolted right on the manifold but here's what I think is the problem. If the carb is bolted on the manifold -not usually possible with Chevy Q-jet manifolds, because the primary throttle plates hit the small ports in the manifold , but possible with a pontiac manifold because of the cutout chamfer around the primaries for the EGR- you might have a severe vacuum leak because the carb doesn't overlap the sides of the manifold openings enough to seal the gasket. The same goes if you have an adapter plate, check it by letting the engine idle and squirting Brake Kleen along the side of the carb gasket, if the idle picks up you have found your problem. The same can be said for the vacuum modulator valve connection on the trans, the PCV hose to the valley pan and any other vacuum connections.
A bad vacuum leak can cause a rough idle and popping/ bogging that will make the car very hard to enjoy.
The trans kickdown cable only affects shift points and line pressures in the trans and the only effect on the engine is lugging if the trans doesn't kick down a gear under heavy load conditions. As pontiacman8 has pointed out you can run forever without it hooked up, if you don't mind manually down shifting when you want to pass.  

David, went back to your RR profile and checked the pic of your engine, looks like you have an adapter plate in there. Check the gasket joints with the Brake Kleen, bet you have a leak. Also wouldn't hurt to have the timing checked.
Steve  

Thanks yall, ill check those gasket joints and what not. I forgot to mention but when the car is running, the smell of the gas is very lean and burns your eyes when your are in the back of the car, so I'm guessing I do have a leak somewhere