Put these on
You want the inlet to be 2.3 inch or 2.5 inch NOT 2.25inch because 2.25 Is the stock pipe, you want the new tip to slip over the pipe.
I haven't seen how they slide but I think 2.5 inch would be the best, but I can't find a link to one.
Outlet 4 inch
Length 7 inch
https://www.ebay.com.au/itm/172294382279
https://www.ebay.com.au/itm/121599832880