These ones can fit the velocity stacks under the cover - but theres about 1/4mm between the top of the filter and the strut tower. And i have my engine slightly angled with a couple of large washers under the left engine mount. You can get shorter ones - but you will have to lose the velocity stacks. The dude on EBAY USA has heaps of stuff for webers - check out his store. Cheers!
Theres probably about 15mm. Im pretty sure there will be enough flow - but if it feels like its choking i might try with out velocity stacks. See how we go when i get it started!