I had a few of these made for my own projects and have extra to share. The spacer is 1/4" aluminum and would be good if you are running one of those pre-made intakes by doppler or malossi. The flange is 3/16 steel with a 26mm hole which I anticipated for a mikuni 24. Weld away! You may need a smidge of filing but mine bolted up no problemo. $10 will get one of each to your door.