Anyone contemplating an EFI install will get into this, so I thought i show you how I've done it.
I used modern Bosch injectors which have a plastic cup at the bottom around the injector nozzle. I did file off the edge of that plastic cup so that the viton (?) O-ring can sit partly inside and against the original recess of the injector opening in the manifold. It sits very snug and well sealed or so it seems. Will need to thest this on the engine later of course.
The original rubber that sits inside the bracket of the original D-jet injectors also fits the new style (3 bar efi) injectors!
The fuel rail was ordered from summit and cut to length, bored and reamed the openings for the injectors (the only thing I commisioned out) and bored and tapped the ends for NPT 3/8".
I used the original studs to also hold the fuel rail down, made small brackets which are held by bored and taped holes in the underside of the fuel rail.