Im building a sb 400 . My friend threw the idea to me about running a tbi set up which id love to do. My questions are would it be best to run a 350 tbi or 454 tbi?

Also heard you can only go so big on your cam?

How big of a head ache am i lookin at?

My build 400 bored .030 over
Stock crank
Stock rods
Flat top pistons
Crane hmv-278-2 cam duration 278/290 lift .467/.494
Stock 997 400sb heads
Roller tip rockers
Edelbrock performer intake.
Long tube headers for 77 chevy truck

Any advice would be super thank you