There is a tremendous amount of info on this site about this subject. Pumpish makes manifolds for these for sale. I have made my own. If you are going to push a lot of boost then it is a must but at low boost levels the stock manifold is fine. And the resonance manifold is a benefit. There really are only two seals to the lower manifold and they do not really go bad and normally the intake to head seals do not go bad and are typically replaced when doing a head gasket.
I do not know what engine number you have but according to the epc there is not a 104032 engine. Did you mean 124032 chassis?