I am dealing with a 454 (early 80's carb'd) which when it is cold will fire right up and go, once it drive it for a while and park it it will not start, acts as if the battery is dead (alternater shows to be charging properly). put a new battery and starter in it and it started up cold fine but once I drove it 25 miles it wont start, same situation but once it sits and cools down for a while it will fire up, to add to this problem the last time I drove it it was blowing black smoke out and lacking power as if it was loading up. also I want to note that the fuel pump does not seem to build up to pressure and shut off as I think it should, it continues to run as long as the ignition is on.