Thanks for your reply.

This restorationhas taken 2.5 years so far. I rebuilt the motor and had it running well before I stripped down the body. So basically I had a #### car with the new motor in it just to test it. That was 12 months ago. It worked just fine. Then I took the motor out and put it on a stand did the body work and dropped the motor back in. At the same time as the body work I did the electric fuel pump, the new exhaust, and the programmable ignition.

I'll try and get the enthusiasm and courage up to go and reprogram the ignition system. If I have no luck there I'll drop in the original dissy and see if it runs on bog standard ignition.

I think all the heavy backfiring was a chance for fuel to go everywhere i.e. puff back out the carbs as well as flood the motor temp (hence the backfire perhaps). So the fuel around the plug threads could still be related.