Starting Problem

[mstngcobrasvt98]

Ok heres the situation. The old starter was bad and we had it rebuilt. Also put a new ring gear on the flywheel since the old one was pretty chewed up along with the old pinion gear. Anyways, now I'm trying to start the thing and it turns the motor over and almost starts but makes a god awful noise when cranking. Does this starter need to be shimmed or anything? Also, I redid plugs and things and I'm not sure what coil goes to what set of plugs. Theres one under the intake box and one on the sidewall close to the distributor. What one goes to which coil plug? And what set of dist. plugs(outer or inner) goes to the intake side and which to the exhaust side? Thanks for your help in advance, the car has been sitting for long enough.