Yes, the EFI self adjusts with altitude. Living at 9000 feet and often driving mountain passes well over 10500 feet I can attest to this. I still have my adapted cold air intake system from behind the passenger wheel, as illustrated in a previous thread.
Can You give Me some idea of how to find your "Previous Thread". Spent some time looking at EFI systems this morning. Jeep gets fresh air in front next to rad. Toyota gets it in front of Driver side tire. Best as I can tell Corvette gets it from on top of rad. Looks like Morgan just tucks into any old place to get rid of it.
