An interesting thread on the MGExp forum relating to the change in the original type of thermostat used on the first MGBs – which matched a recirc port cast into the cylinder head.
The forum discusses how to emulate this original spec with a modern type thermostat and using a blanking sleeve to improve cooling – if you have overheating problems.
Food for thought ………. https://www.mgexp.com/forum/mgb-and-gt-forum.1/anyone-experienced-problems-using-a.4034575/
Another article i have found on the same subject on the British Car Forum at ……. https://www.britishcarforum.com/bobmuenchausen/12299.html
MGB tips mods and maintenance 