At least a year!?! That would certainly help explain why I haven't seen more of these on other Panteras!
Certainly you could fit upright "stacks" under the standard engine cover, and I've seen some great examples on this forum where that's been done. May be easiest for a race' application where the shorter runner length is tuned towards higher rpms ... and where the engine can be lowered.
I just did a search on this forum under "IR EFI" and found a bunch of examples of low profile set-ups, including a thread on the Morrison intake. Forgot what a great repository of info this forum provides!! (Thanks George!)