In April 10, 2020, Gary Edwards in Kernersville, NC, USA wrote:
"I made my own using MGB HS4/HIF air cleaner velocity stacks. Bought on BST for $20 plus shipping. I made a jig for my radial arm saw and cut it in half to reduce the height, then polished it up and put it inside the original MGA air cleaner. Held in with 2 countersunk screws from the back. I believe it did improve performance some and may also be why I do not get run on using regular ethanol gas".