H4 (same as MGA) were fitted to works coopers as an upgrade, as standard it would have been fitted with HS2's so the H4 setup it the better one to have! Main reason was the fuel lines use a banjo type fitting and the float bowls had a brass floats and not plastic.
Hope this helps
Oz Cooper
Classic Mini Product Manager UK
Helpful Links:
Code of ConductFAQsMoss Europe LtdDisclaimer: Working on automobiles is inherently dangerous. Moss Motors, Ltd. is not liable for injury or damage due to incorrect installation or use of their products. All products are sold with the understanding that the safe and proper installation and use of the products is the customer’s responsibility. Follow factory workshop manual procedures and instructions, but use current shop safety standards and common sense. Some tasks will require professional advice or services which Moss Motors cannot provide.