Originally Posted by magredvet
The tensioner is original, but the pulley is replaced by a one supplied in the pulley saver kit, which is why it has a rounded shape on the outside edge. my belt was 'hanging' over this rounded edge, but putting the washer behind it, spaces it out, away from the block, and the belt rides more central
I've contacted Needswings, waiting to place an order for the enlarged pulley.
Order placed, thanks everyone.