My old beast is "as above". I just blanked each end of the EGR .. but I cleaned the EGR out so it was moving freely and then just left it in place/connected.
I put a plate between the EGR and inlet manifold and another between the EGR and the pipe from the exhaust. This completely isolates the EGR from getting anything in it from either direction so that it can't gum up (which it might if either end was open).
I used the plate at the inlet manifold because the inlet manifold can collect oil vapour or crankcase blow-by (previous owner seemed to overfill the engine oil, judging by how much oil was in there/the dipstick when I bought it..) but seeing that gave me the thought that maybe I should also isolate the EGR from that side too.
I'd have preferred to put the second plate (going in to the EGR) lower down the pipe work - closer to the exhaust manifold - but on that end the bolts were corroded and I didn't want to risk shearing one off. As it is, exhaust can travel up the pipes to the EGR.. but this should be minimal since it's a dead end.
My beast revs a lot more easily and feels more powerful without the EGR channel being available. EGR passes exhaust gas into the inlet manifold.. so the inlet manifold ends up looking like an old-school (pre-cat) silencer - full of soot and in my case oil. That gets drawn into the combustion chamber, so it can't possibly be better for the engine than clean air.
I also noticed I don't get any soot out of the exhaust when I boot it... which is the opposite of what I expected. I guess the inlet charge burns more cleanly with fresh air rather than soot and oil residue..? I dunno..
Ralf S.