THERMOSTAT HOUSING BOLT WHEN SANDWICH PLATE FITTED

On late A plus engines the factory changed over to bolts rather than a stud on thermostats with a sandwich plate underneath them, all are interchangable as the cylinder head threaded hole was standard. 5/16"unc 2.5"long(2 & 9/16" to be exact (63.5mm)) with tuflock patch to secure.