403 Fuel Pump AC type UG stripped threads

[mikebro]

I've done a few hundred miles after rebuilding the 403's engine. I had already rebuilt the fuel pump with a repair kit a few years ago. I remember at the time thinking that several of the diaphragm flange bolts were a bit dodgy. Anyhow, now, there is a slight petrol weep at the flange, and three of the six bolts won't tighten. Has anyone on the forum made a repair using helicoils or V-coils? I'm keen to know if there is enough metal around the female threads to take a thread insert. Also, are the bolts 10-32 Unified or 2BA? I'm suspecting 10-32 as mine will only go about 3 turns into a 2BA nut.
Anyway, any first hand experience of all this would be very useful. And confirmation of the bolt thread type.

Cheers

Mike