Yeah, mine are on the inlet side, but still, difficult to get to. I am able to (just) get a stillson wrench to grip. The first challenge is to remove the injector leak-off pipe without ruining it, ; take a large pin punch and whack the side of the hexagon nut of the leakoff pipe a good blow from the top. Then gently and carefully loosen the hold-down nut. I subsequently modified mine to have fuel-line hose between each injector so as to have some flexibility. I have been unable to ascertain what the correct injector seal is. - I seem to have an aluminium heat washer at the injector tip, but no copper washer for a seal. There is a tapered seat in the cylinder head
without a washer that seems to be the only sealing surface. The engine
seems to run fine like that. Holding thumbs!