There should be a good sized relief in the balancer to get at that bolt, well good enough to get a 3/8" drive socket extension thru it so don't know why you're having trouble there. The plastic gets cooked on these cars and I don't think you ned to replace them, just get some shrink wrap or split loom and patch them up, as long as the conductors are still intact. All the steel lines should be fine unless they are kinked or rusted just leave them and reuse.

You can and should replace all the plenum donuts, plastic injector holders, rubber lines that go to them and possibly the lower CIS plenum.

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Chas

Had a 380SL, 450SL, 380SEL, 420SEL, 500SEL

Got a Euro 500SEC right now.