carb or efi

Wow... with the information you gave us (zero) on the build, it's impossible to answer.
What's your engine combo, what parts (cam/compression/exhaust/trans/...)
How comfortable are you tuning carbs? Which brand/style?
How comfortable are you with programming efi systems? Even the best self-learning systems will require some manual input... Which systems are you considering? What is your fuel delivery system like? EFI requires a whole different support system than carbs...
"90% strip"- any particular class?
Throw us a bone, here...