Water rails are designed to simplify the cooling system and plumbing of the engine when installed in-line in a RWD car. The engine has water outlets at the back of the head, which in most RWD applications foul the bulkhead if you retain the original outlet housings. The water rails are designed with a narrow profile to transfer this outlet to the front of the engine making the plumbing simpler and neater. Use fitting kit FD471. Note that thermostat housing is supplied at extra cost. Only suitable for kits cars - coil mounting lugs foul Escort bulkhead.