Help Tracking Down Starting/Running Issue

[katwalk]

I have had this truck for a few months now and it always cranked right up. A few weeks ago I drove it to the Squarebody Yard Party, about 80 miles away. When I was trying to leave, the truck would not start. I cranked on it for a while and it finally started - rough at first but then seemed fine after that. Over the next couple of days, on a couple of occasions while cruising down the road, the truck would fall on its face for a second or two then keep going. A few days later, I was out running errands and it and it would not start again.

I got it home and my first thought was carburetor. Long story shortened , I bought a rebuilt quadrajet for it. It is a later model QJet with the electric choke. I was having trouble starting it after installing the new QJet, so popped the cap off the Dist to find it a rusty mess - I was amazed it ran at all.

So, in goes a new Dist. I have checked and rechecked the timing to make sure I knew where top dead center was and the new plug wires were installed correctly - all good there.

I can not for the life of me get it to run. It cranks and cranks and sometimes acts like it wants to run but wont. One time I got it to run and it smoked like crazy out of the tailpipes. It idled roughly while I tinkered with Idle Air screws and distributor/timing then finally died.

I have looked into the carb while pressing the throttle and can see fuel flowing. I have pulled a plug wire and installed it on a spare spark plug and can see it sparking. I pulled the valve cover and can see the engine has not had the best life (sludge), so I am wondering if a stretched timing chain could be preventing me from actually getting the timing right. Thoughts? Ideas?

Thanks - Farrell