hello,my driveshaft seal was leaking so ive replaced it with an nos one which didn,t seem tight time will tell, just wondered if its best to put an original drive shaft in,i dont know whats in now,theres a £100 quid diference in prices,also the engine sump seems to be ouzing oil through the metel itself ,when i remove it will a gasket on itself do,or sealant each side and the gascket sandwiched ,thanks