ignition problems

I have been having problems with setting the timing and would like to know ,when looking on top of black distributor cap ,what are the correct plug lead connections.I can start and seems to run ok but after about 3/4 minutes driving engine cuts out and will not start.Go back home,towed, reset timing(flywheel mark,cam gear mark and crankshaft @ TDC,car will start but cuts out again.Any advice would be welcome.Thanks in advance

It won't be your plug leads as if they are not in the correct order it won't start, or at best misfire horribly. This could either be ignition or fuel problems and so you need to be methodical in working through it. Condensors get hot by their nature and can misbehave, as can coils, both exasperated by points in poor condition. None of the above parts are expensive or difficult to fit and so would be a good place to start. Less likely are things like the breather for the fuel tank being blocked causing a vacuum, or the filter on the fuel pick up pipe being blocked, again causing fuel starvation. A simple check for these is when the car has stopped whip off the air filter and look down the carb while working the throttle. You should see and smell neat petrol being squirted down the chokes by the accelerator jets, if not that suggests the carb has run out of fuel.
Don't forget that it can be a combination of issues and one tipping the system over the edge