I've got a core drill I use for making 55mm holes through brickwork,works a treat for drilling out the cat in the headers
No Alan,take off the end can from the headers,look inside and you'll see the cat,I used a 55mm core drill to remove the centre then chip off the rest of the material belonging to the cat Hope this helps pal
Preferably yes, doesn’t matter what way you go about it, you’ll have to map it to get the optimum fuelling