I'm pretty sure I will need tall covers but not sure which one are the best fit. Here's what I have: Promaxx heads, comp cam 1.6 rockers, trick flow track heat upper and lower. Plenty of hood clearance but would rather not use a intake spacer. Any suggestions would be greatly appreciated. Also I have found 1,000's of tall options for 289, 302, 351W but most of them say "will not work for EFI". Why is that?