Alive Dead Alive

Is it still points ignition or did you upgrade it to electronic? If it's points, check/replace the condenser in the distributor and the coil. If it's electronic check/replace the ECU.

Also, is it still the stock 2-bbl. Carter? I know when I was still running that carb on my 318 I had a LOT of problems with gas boiling in the carb. You can find out if it's that by driving around until the car is warmed up and if/when it stalls or won't start again, take off the air cleaner and look at the carb. If it reeks of gas and the carb and air cleaner are wet with gas then you'll know.