The original metal oil pipe from the block to the filter head has been made obsolete by Rover but this use this Braided oil pipe from the block to filter head instead. Pre 1992 engines have 5/8" block union and 1/4" npt thread for the filter head 12A engines from 1992 on have 11/16"UNF block and filter head. Therefore this kit is 5/8" block union and 1/4"npt filter head
