Ive got an issue with the running of my pinto, it runs twin weber 45's and Is ported, cam'd etc etc. The problem started yesterday when I took the kit car for a blast round a disused industrial estate, first off it was fine but after about 30 mins it became rough as in touching the throttle would make it cough and bang out the exhaust and I can smell unburnt fuel. So today I started it back up and when cold it was fine again but after about 20 odd mins ticking over and revving it started doing it again, its like something is breaking down with the heat ??.
Ive changed the coil, plugs etc but something is leading me to think it could be the dizzy, it runs a bosch distributor with the ignition module on the side, has anyone had any experience with them or had a similar fault before




The things I have checked are

plugs = new
col = new
cap = new
leads checked
red top pump = checked + set to 2ish psi, god steady flow with pipe off
filer king = new
carbs stripped and checked by myself and cant see anything untoward, all jets clear and floats are closing etc, jets sizes have been confirmed by Northampton motorsport
good engine earth
good live feed to starter and electrics etc
fresh fuel


Any ideas ??